francesca perretti - Academia.edu (original) (raw)
Papers by francesca perretti
European Journal of Pharmacology, 1990
Archives Internationales De Pharmacodynamie Et De Therapie, 1990
Advances in experimental medicine and biology, 1991
1. Adv Exp Med Biol. 1991;298:241-8. Efferent function of capsaicin-sensitive nerves and neurogen... more 1. Adv Exp Med Biol. 1991;298:241-8. Efferent function of capsaicin-sensitive nerves and neurogenic vasodilation in rat mesenteric circulation. Manzini S, Tramontana M, Perretti F. Istituto Farmacobiologico Malesci, Pharmacology Department, Florence, Italy. ...
We have studied the effect of epithelium removal (rubbing) and the endopeptidase 24.11 inhibitor,... more We have studied the effect of epithelium removal (rubbing) and the endopeptidase 24.11 inhibitor, thiorphan, on the contractile response of the guinea-pig isolated bronchi (atropine and indomethacin in the bath) produced by electrical field stimulation, capsaicin or exogenously administered tachykinins (substance P and neurokinin A). (2) The response to field stimulation, thought to involve release of endogenous tachykinins, was potentiated by thiorphan in both epithelium-free and intact bronchi. However, at low frequencies (1-5 Hz), the effect of thiorphan was more evident in intact preparations. (3) The response to capsaicin was enhanced by both epithelium removal and thiorphan administration. (4) The response to exogenous substance P or neurokinin A was potentiated by thiorphan both in epithelium-free and intact bronchi. (5) Capsaicin (1 gM) evoked a consistent release of substance Plike immumoreactivity (determined by radioimmunoassay) and tachykinin-like immunoreactivity (determined by a novel immunoenzyme assay), which was enhanced by thiorphan in both epithelium-free and intact bronchi. (6) These findings suggest that a thiorphan-sensitive mechanism, presumably 'enkephalinase' (endopeptidase 24.11), plays a major role in inactivating endogenous tachykinins released from sensory nerves and that this enzymatic activity is still present after removal of the bronchial epithelium.
General Pharmacology: The Vascular System, 1991
The ability of capsaicin and antidromic stimulation of perivascular nerve fibers to release senso... more The ability of capsaicin and antidromic stimulation of perivascular nerve fibers to release sensory neuropeptides (SP-LI and CGRP-LI) have been investigated in rat mesenteric arteries and veins. 2. Both in mesenteric arteries and veins substantial SP-LI and CGRP-LI tissue levels were measured. A significant reduction in sensory neuropeptides levels was observed in tissues obtained from capsaicinpretreated animals. 3. Superfusion of isolated vessels with capsaicin (1 #M) produced a prompt and remarkable release of both SP-LI and CGRP-LI, which can be evoked only once in each preparation. 4. Electrical field stimulation (EFS, 20 Hz, 50 V, 0.5 reset, trains of 10 see every 20 see for 15 rain) of isolated vessels resulted in a significant release of CGRP-LI. This release was significantly greater in veins as compared to arteries. EFS-indueed CGRP-LI release was unaffected by atropine or guanethidine and absent in preparations obtained from eapsaiein-pretreated rats. 5. These neurc, ehemical findings further suggest that the local release of sensory neuropeptides from capsaicin-sensitive nerve endings might be important in the regulation of mesenteric circulation.
Pulmonary Pharmacology, 1995
The role of airway inflammation, induced by weekly antigen challenge, in the airway hyperresponsi... more The role of airway inflammation, induced by weekly antigen challenge, in the airway hyperresponsiveness to vagal (whole and NANC components) nerve stimulation and to neurotransmitters (acetylcholine and selective agonists for tachykinin NK1 and NK2 receptors) has been studied in the guinea-pig. Primarily, the time course (3, 7 and 14 days following the last challenge) of the effects of repeated aerosol antigen challenge on airway inflammation and bronchoalveolar fluid cellular composition was investigated. At 7 days following the last antigen challenge a maximal (as compared to 3 and 14 days) inflammatory response, in terms of a diffuse mild to marked infiltration of eosinophils, neutrophils and lymphocytes, was evident throughout pulmonary tissues. Only at this time some evidence of eosinophilia and neutropenia was detectable in BAL fluids. In these animals there was a normal bronchial responsiveness to iv administration of acetylcholine, selective synthetic agonists for the tachykinin NK2 receptors and capsaicin. On the other hand a remarkable airways hyperresponsiveness to iv administration of selective agonists for tachykinin NK1 receptors, as well as electrical stimulation of the vagal nerves (in presence and in absence of atropine), was detected. As a whole, these data indicate that at the peak of the inflammatory airway response following multiple antigen challenge there is a selective hyperresponsiveness to stimulation of vagal (mainly the non-adrenergic, non-cholinergic component) nerves associated with an increase in tachykinins (NK-1)-mediated bronchospasm.
Regulatory Peptides, 1988
Regulatory Peptides, 1988
Pharmacological Research, 1990
Naunyn-Schmiedeberg's Archives of Pharmacology, 1990
We have studied the effect of epithelium removal (rubbing) and the endopeptidase 24.11 inhibitor,... more We have studied the effect of epithelium removal (rubbing) and the endopeptidase 24.11 inhibitor, thiorphan, on the contractile response of the guinea-pig isolated bronchi (atropine and indomethacin in the bath) produced by electrical field stimulation, capsaicin or exogenously administered tachykinins (substance P and neurokinin A). (2) The response to field stimulation, thought to involve release of endogenous tachykinins, was potentiated by thiorphan in both epithelium-free and intact bronchi. However, at low frequencies (1-5 Hz), the effect of thiorphan was more evident in intact preparations. (3) The response to capsaicin was enhanced by both epithelium removal and thiorphan administration. (4) The response to exogenous substance P or neurokinin A was potentiated by thiorphan both in epithelium-free and intact bronchi. (5) Capsaicin (1 gM) evoked a consistent release of substance Plike immumoreactivity (determined by radioimmunoassay) and tachykinin-like immunoreactivity (determined by a novel immunoenzyme assay), which was enhanced by thiorphan in both epithelium-free and intact bronchi. (6) These findings suggest that a thiorphan-sensitive mechanism, presumably 'enkephalinase' (endopeptidase 24.11), plays a major role in inactivating endogenous tachykinins released from sensory nerves and that this enzymatic activity is still present after removal of the bronchial epithelium.
Naunyn-Schmiedeberg's Archives of Pharmacology, 1990
1. In the presence of atropine and guanethidine (3 gmol/1 each), electrical field stimulation (1-... more 1. In the presence of atropine and guanethidine (3 gmol/1 each), electrical field stimulation (1-20 Hz) produced frequency-dependent relaxations of the histamine-(3 gmol/1) induced vascular tone in isolated rings from the guinea-pig pulmonary artery. The electricallyevoked relaxations were abolished by tetrodotoxin (1 gmol/1). The amplitude of these nerve-mediated, nonadrenergic non-cholinergic (NANC) relaxations was unaffected by removal of the vascular endothelium produced through rubbing of the internal surface. 2. Capsaicin (1 gmol/1) produced a prompt and sustained relaxation of the histamine-induced tone which was unaffected by removal of the endothelium. A second application of capsaicin 60-120 rain later had no further relaxant effect, indicating desensitization. After in vitro capsaicin desensitization, the electrically-evoked NANC relaxations were abolished, both in the presence or absence of the vascular endothelium. 3. Substance P evoked a prompt and transient relaxation in precontracted arterial rings with intact endothelium and a transient small contraction in rings in which the endothelium had been mechanically removed. The selective NK-I receptor agonist, [Pro9]-substance P sulfone closely mimicked the relaxation produced by substance P while the selective NK-2 or NK-3 receptor agonists had no relaxant effect. Tachyphylaxis to substance P did not modify the amplitude of the capsaicin-induced relaxation. 4. Human alpha calcitonin gene-related peptide (CGRP) produced a prompt and sustained relaxation both in the presence and absence of the vascular endothelium. 5. Ruthenium red (10 gmol/1) blocked the relaxation to capsaicin while leaving unaffected the relaxation to electrical field stimulation or CGRP (0.1 gmol/1). 6. Both substance P (SP)and CGRP-like immunoreactivities (LI) were detected in extracts of the guinea-pig pulmonary artery. Capsaicin (1 gmol/1) evoked a prompt and simultaneous outflow of both SP-and CGRP-LI. A second application of capsaicin 60 rain later failed to increase SP-or CGRP-LI out-Send offprint requests to C. A. Maggi at the above address flow, indicating complete desensitization. A small but clearly detectable release of both SP-LI and CGRP-LI was also evoked by electrical field stimulation. 7. These findings provide evidence that the neurogenic NANC vasodilation in the guinea-pig pulmonary artery is due to antidromic activation of peripheral endings of capsaicinsensitive primary afferents. Endogenous CGRP is a likely mediator for this vasodilation. No evidence was found that endogenous SP might contribute to vasodilation by activating NK-I receptors on endothelial cells.
Journal of Clinical Investigation, 1994
We have previously reported that human eosinophil granule major basic protein and synthetic catio... more We have previously reported that human eosinophil granule major basic protein and synthetic cationic proteins such as poly-L-arginine and poly-L-lysine, can increase airway responsiveness in vivo. In the present study, we have investigated whether activation of sensory C-fibers is important in this phenomenon. Dose-response curves to methacholine were constructed before and 1 h after intratracheal instillation of poly-L-lysine in anaesthetized spontaneously breathing rats, and the concentration of methacholine required to induce a doubling in total lung resistance was calculated. Poly-L-lysine induced a fivefold increase in airway responsiveness, which was inhibited by neonatal capsaicin treatment and potentiated by phosphoramidon (100 jtg/ml). Furthermore, pretreatment with either CP, 96-345, or RP-67580 two selective NK-1 receptor antagonists inhibited poly-L-lysine-induced airway hyperresponsiveness and plasma protein extravasation. In vitro, cationic proteins stimulated the release of calcitonin gene-related peptidelike immunoreactivity from perfused slices of the main bronchi. Our results demonstrate that cationic proteins can activate sensory C-fibers in the airways, an effect which is important in the subsequent development of airway hyperresponsiveness and plasma protein extravasation. Cationic proteins may therefore function as a link between inflammatory cell accumulation and sensory nerve activation. (J.
European Journal of Pharmacology, 1993
The pharmacological actions of the new xanthine, isbufylline, were evaluated in several models of... more The pharmacological actions of the new xanthine, isbufylline, were evaluated in several models of airway hyperresponsiveness and airway inflammation in guinea pigs. At a dose (106 #tool kg-1 i.p.) providing complete protection against acetylcholine aerosol-induced dyspnea in the guinea pig, isbufylline inhibited platelet activating factor (PAF)-and antigen-induced eosinophil infiltration into bronchoalveolar lavage fluid 24 h after challenge of normal and actively immunized guinea pigs, respectively. In addition, this dose of isbufylline also inhibited capsaicin-induced extravasation of protein into bronchoalveolar lavage fluid. Isbufylline, 4.2 /~mol kg-1 i.v., significantly inhibited PAF-induced bronchial hyper-responsiveness to i.v. histamine, without exerting evident bronchodilator activity. On the other hand the bronchodilator, salbutamol, at a dose (10.4 /~mol kg-~ i.p.) shown to be equieffective to isbufylline (106 /zmol kg-1 i.p.) for blocking acetylcholine aerosol-induced dyspnea, had no protective action against PAF-or antigen-induced eosinophil recruitment in bronchoalveolar lavage fluid, or against capsaicin-induced plasma protein extravasation. Furthermore, salbutamol (3.5 #mol kg-~) significantly potentiated allergen-induced cell infiltration and PAF-induced bronchial hyperresponsiveness. The results suggest that isbufylline can exert significant anti-inflammatory actions in guinea pig airways, in addition to its brouchodilator activity. These pharmacological activities are not shared by the/32-adrenoceptor agonist, salbutamoi.
European Journal of Pharmacology, 1988
The effects of intra-and extraluminal capsaicm administration were evaluated in isolated perfused... more The effects of intra-and extraluminal capsaicm administration were evaluated in isolated perfused rat mesentenc bed. Capsalcln (10 nM-1 #M) produced a potent concentration-dependent relaxaUon of the tonic vasoconstriction induced by norepinephrine (1 #M) but not by high-K + (60 mM). The capsaacin-lnduced relaxation was nearly abolished m preparations pretreated in vitro with a high concentration of capsaicm (1 #M, for 10 min, 1 h before). Capsaicin-induced relaxation was reduced but not abolished m preparations obtained from rats pretreated neonatally with capsaicin. The capsaicin effects were unaffected by atropine, guanethidine, propranolol, hexamethonium or tetrodotoxm. The observation that capsaicm (0.1 #M)-induced relaxation was virtually abolished in presence of the proteolytic enzyme a-chymotrypsin (1 U/ml) supports the involvement of neuropepude(s) in this response. Bolus injections of calcitonin gene-related peptide (CGRP) elicited a potent and rapidly ensuing relaxation which underwent tachyphylaxis. However, no cross-desensitization with capsaicin was observed. It ~s concluded that activation of capsaicin-sensitive sensory fibers could release neuropeptides locally with a potent effect on intestinal blood flow.
European Journal of Pharmacology, 1995
The antibronchospastic activity against acetylcholine, antigen, histamine plus platelet-activatin... more The antibronchospastic activity against acetylcholine, antigen, histamine plus platelet-activating factor (PAF) or the selective tachykinin neurokinin (NK) 1 and NK 2 receptor agonists of the novel tachykinin NK 2 receptor antagonist, MEN10,627 (cyclo(Met-Asp-Trp-Phe-Dap-Leu)cyclo(2/3-5/3)), was studied in anesthetized guinea-pigs. MEN10,627 (30-100 nmol/kg i.v.) reduced in a dose-dependent manner the bronchospasm induced by the tachykinin NK 2 receptor agonist [/3AlaS]neurokinin A-(4-10) and the effect of the highest dose lasted up to 5 h from its administration. Conversely, airway constriction induced by the NK l receptor agonist [Sar9]substance P sulfone or acetylcholine was unaffected by MEN10,627 up to a dose of 3 tzmol/kg i.v. In animals sensitized with ovalbumin and pretreated with the endopeptidase inhibitor phosphoramidon, the aerosolized antigen produced a bronchospasm which was inhibited by MEN10,627 (30-100 nmol/kg i.v.) but not by the tachykinin NK 1 receptor antagonist, (+)-CP96,345 ([2R,3R-cisand [2S,3S)-cis-2-(diphenylmethyl)-N-[(2-methoxyphenyl)-methyl]-lazabicyclo[2.2.2]octan-3-amine]) (3 tzmol/kg i.v.). Both MEN10,627 (30-100 nmol/kg i.v.) and (_+)-CP96,345 (30-300 nmol/kg i.v.) reduced the PAF-induced hyperresponsiveness to histamine, without affecting the hypotension induced by PAF or the bronchospasm induced by histamine in guinea-pigs not exposed to PAF, showing the involvement of both tachykinin NK 1 and NK 2 receptors in this model. In summary, MEN10,627 behaves as a potent, selective and long-lasting tachykinin NK 2 receptor antagonist in vivo. Further, tachykinin NK 2 receptors could be activated during allergic responses and in the development of airway hyperresponsiveness.
Drug Development Research, 1991
In vitro and in vivo studies on the effects of the alpha-adrenoceptor blocker IPi66 (1-(2-ethoxy-... more In vitro and in vivo studies on the effects of the alpha-adrenoceptor blocker IPi66 (1-(2-ethoxy-2-(3'-pyridyl)ethyl)-4-(2'-methoxy-phenyl)piperazine) on urethral tone in rats. Drug Dev. Res. 23: 35-46, 1991. IP/66 (1-(2-ethoxy-2-(3'-pyridyl)ethyl)-4-(2'-methoxy-phenyl)piperazine is a newly synthetized and stereoselective alpha-adrenoceptor blocking drug. This compound exhibits preferential blocking activity in postjunctional as compared to prejunctional alpha-adrenergic responses. Furthermore, IP/66 inhibits phenylephrine-induced motor response in human and rat prostatic tissue and phenylephrine-, DMPP-and EFS-induced motor responses in rat urethral tissues, being equieffective or even more potent than prazosin. Like prazosin, intravenous administration of IP/66, at doses at which no hypotensive effect is observed, induces a marked inhibition of phenylephrine or DMPP-induced increase in urethral perfusion pressure, in anaesthetized pithed rats. Finally, IP/66 administration exerts beneficial effects in animals with surgically-or pharmacologically-induced urethral outflow obstruction.
British Journal of Pharmacology, 1989
Bradykinin and capsaicin were compared for their ability to elicit functional effects and to rele... more Bradykinin and capsaicin were compared for their ability to elicit functional effects and to release sensory neuropeptides from guinea-pig isolated perfused hearts. 2 Both bradykinin (1O/M) and capsaicin (1 pM) produced a marked increase in coronary flow, a large positive chronotropic effect and a significant reduction in contractile strength. These actions were associated with a marked release of substance P-like immunoreactivity (SP-LI) and calcitonin gene-related-like immunoreactivity (CGRP-LI). The percentage of the tissue content of SP-LI and CGRP-LI released by each agent was similar, although bradykinin was less effective than capsaicin. The ratio of SP-LI/CGRP-LI released by both agents was similar to that present in cardiac tissue. 3 Neuropeptide release could be evoked only once with capsaicin but at least four times with bradykinin. Also, functional responses to capsaicin underwent desensitization. After either in vitro or systemic capsaicin pretreatment, the release of SP-LI and CGRP-LI by bradykinin was reduced and the positive chronotropic effect of bradykinin was significantly reduced, while the increase in coronary flow and negative inotropic responses remained unchanged. 4 Pretreatment with indomethacin (10/M) strongly antagonized the release of SP-LI and CGRP-LI by bradykinin and reduced the increase in heart rate. 5 These findings suggest that activation by bradykinin (probably through indirect mechanisms) of capsaicin-sensitive sensory nerves in the heart, leads to a local release of sensory neuropeptides. These neuropeptides, in turn, could participate in determining the complex functional effects of this kinin on cardiac performance.
British Journal of Pharmacology, 1988
Both bradykinin and capsaicin infusion evoked a marked increase in the outflow of substance P-(SP... more Both bradykinin and capsaicin infusion evoked a marked increase in the outflow of substance P-(SP-LI) and calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) from guinea-pig isolated, perfused heart. After acute exposure to capsaicin in vitro, or in hearts taken from animals pretreated in vivo with capsaicin, bradykinin failed to induce any release. The positive chronotropic effect of bradykinin was reduced after acute capsaicin administration. The effect of bradykinin in the guinea-pig heart could be mediated, at least partly, by release of neuropeptides from peripheral endings of capsaicin-sensitive sensory neurones.
British Journal of Pharmacology, 1989
Administration of arachidonic acid (AA) both in vitro and in vivo elicited prominent contractile ... more Administration of arachidonic acid (AA) both in vitro and in vivo elicited prominent contractile responses in guinea-pig airways, which were markedly reduced after capsaicin desensitization. Furthermore, AA superfusion elicited a significant calcitonin gene-related peptide-like immunoreactivity release from isolated bronchi. It is suggested that at least part of the bronchomotor actions of AA rely upon stimulation of capsaicinsensitive primary afferents.
Journal of Autonomic Pharmacology, 1992
Intravenous administration of substance P (SP) or of the NK, selective agonist [P-Ala4, Sar9, Met... more Intravenous administration of substance P (SP) or of the NK, selective agonist [P-Ala4, Sar9, Met (O,)ll] SP-(4-1 I) increased vascular permeability in the urinary bladder of urethane-anaesthetized rats, providing evidence for an NK, receptor-mediated inflammatory response. 2. BW 755C, a dual inhibitor of arachidonate cyclo-oxygenase and lipoxygenase, significantly reduced the plasma extravasation induced by SP, but did not modify the effect of v-Ala4, Sar9, Met (0,)11] SP-(4-1 1). 3 SP-induced microvascular leakage was also inhibited by systemic pretreatment with indomethacin or with the prostaglandin receptor antagonist SC-19220, while it was unaffected by the selective 5-lipoxygenase inhibitor BW A4C or the leukotriene antagonist FPL 557 12. 4 Pretreatment of rats with the mast cell degranulating agent compound 48/80 significantly attenuated the inflammatory effect of SP. Indomethacin administration to 48/80-pretreated animals failed to produce further inhibition. 5 These findings indicate that intravascular SP promotes plasma exudation in rat urinary bladder through an NK,-mediated effect on venular permeability and the release of cyclo-oxygenase metabolites of arachidonic acid. The latter effect largely derives from the interaction of the neuropeptide with mast cells.
European Journal of Pharmacology, 1990
Archives Internationales De Pharmacodynamie Et De Therapie, 1990
Advances in experimental medicine and biology, 1991
1. Adv Exp Med Biol. 1991;298:241-8. Efferent function of capsaicin-sensitive nerves and neurogen... more 1. Adv Exp Med Biol. 1991;298:241-8. Efferent function of capsaicin-sensitive nerves and neurogenic vasodilation in rat mesenteric circulation. Manzini S, Tramontana M, Perretti F. Istituto Farmacobiologico Malesci, Pharmacology Department, Florence, Italy. ...
We have studied the effect of epithelium removal (rubbing) and the endopeptidase 24.11 inhibitor,... more We have studied the effect of epithelium removal (rubbing) and the endopeptidase 24.11 inhibitor, thiorphan, on the contractile response of the guinea-pig isolated bronchi (atropine and indomethacin in the bath) produced by electrical field stimulation, capsaicin or exogenously administered tachykinins (substance P and neurokinin A). (2) The response to field stimulation, thought to involve release of endogenous tachykinins, was potentiated by thiorphan in both epithelium-free and intact bronchi. However, at low frequencies (1-5 Hz), the effect of thiorphan was more evident in intact preparations. (3) The response to capsaicin was enhanced by both epithelium removal and thiorphan administration. (4) The response to exogenous substance P or neurokinin A was potentiated by thiorphan both in epithelium-free and intact bronchi. (5) Capsaicin (1 gM) evoked a consistent release of substance Plike immumoreactivity (determined by radioimmunoassay) and tachykinin-like immunoreactivity (determined by a novel immunoenzyme assay), which was enhanced by thiorphan in both epithelium-free and intact bronchi. (6) These findings suggest that a thiorphan-sensitive mechanism, presumably 'enkephalinase' (endopeptidase 24.11), plays a major role in inactivating endogenous tachykinins released from sensory nerves and that this enzymatic activity is still present after removal of the bronchial epithelium.
General Pharmacology: The Vascular System, 1991
The ability of capsaicin and antidromic stimulation of perivascular nerve fibers to release senso... more The ability of capsaicin and antidromic stimulation of perivascular nerve fibers to release sensory neuropeptides (SP-LI and CGRP-LI) have been investigated in rat mesenteric arteries and veins. 2. Both in mesenteric arteries and veins substantial SP-LI and CGRP-LI tissue levels were measured. A significant reduction in sensory neuropeptides levels was observed in tissues obtained from capsaicinpretreated animals. 3. Superfusion of isolated vessels with capsaicin (1 #M) produced a prompt and remarkable release of both SP-LI and CGRP-LI, which can be evoked only once in each preparation. 4. Electrical field stimulation (EFS, 20 Hz, 50 V, 0.5 reset, trains of 10 see every 20 see for 15 rain) of isolated vessels resulted in a significant release of CGRP-LI. This release was significantly greater in veins as compared to arteries. EFS-indueed CGRP-LI release was unaffected by atropine or guanethidine and absent in preparations obtained from eapsaiein-pretreated rats. 5. These neurc, ehemical findings further suggest that the local release of sensory neuropeptides from capsaicin-sensitive nerve endings might be important in the regulation of mesenteric circulation.
Pulmonary Pharmacology, 1995
The role of airway inflammation, induced by weekly antigen challenge, in the airway hyperresponsi... more The role of airway inflammation, induced by weekly antigen challenge, in the airway hyperresponsiveness to vagal (whole and NANC components) nerve stimulation and to neurotransmitters (acetylcholine and selective agonists for tachykinin NK1 and NK2 receptors) has been studied in the guinea-pig. Primarily, the time course (3, 7 and 14 days following the last challenge) of the effects of repeated aerosol antigen challenge on airway inflammation and bronchoalveolar fluid cellular composition was investigated. At 7 days following the last antigen challenge a maximal (as compared to 3 and 14 days) inflammatory response, in terms of a diffuse mild to marked infiltration of eosinophils, neutrophils and lymphocytes, was evident throughout pulmonary tissues. Only at this time some evidence of eosinophilia and neutropenia was detectable in BAL fluids. In these animals there was a normal bronchial responsiveness to iv administration of acetylcholine, selective synthetic agonists for the tachykinin NK2 receptors and capsaicin. On the other hand a remarkable airways hyperresponsiveness to iv administration of selective agonists for tachykinin NK1 receptors, as well as electrical stimulation of the vagal nerves (in presence and in absence of atropine), was detected. As a whole, these data indicate that at the peak of the inflammatory airway response following multiple antigen challenge there is a selective hyperresponsiveness to stimulation of vagal (mainly the non-adrenergic, non-cholinergic component) nerves associated with an increase in tachykinins (NK-1)-mediated bronchospasm.
Regulatory Peptides, 1988
Regulatory Peptides, 1988
Pharmacological Research, 1990
Naunyn-Schmiedeberg's Archives of Pharmacology, 1990
We have studied the effect of epithelium removal (rubbing) and the endopeptidase 24.11 inhibitor,... more We have studied the effect of epithelium removal (rubbing) and the endopeptidase 24.11 inhibitor, thiorphan, on the contractile response of the guinea-pig isolated bronchi (atropine and indomethacin in the bath) produced by electrical field stimulation, capsaicin or exogenously administered tachykinins (substance P and neurokinin A). (2) The response to field stimulation, thought to involve release of endogenous tachykinins, was potentiated by thiorphan in both epithelium-free and intact bronchi. However, at low frequencies (1-5 Hz), the effect of thiorphan was more evident in intact preparations. (3) The response to capsaicin was enhanced by both epithelium removal and thiorphan administration. (4) The response to exogenous substance P or neurokinin A was potentiated by thiorphan both in epithelium-free and intact bronchi. (5) Capsaicin (1 gM) evoked a consistent release of substance Plike immumoreactivity (determined by radioimmunoassay) and tachykinin-like immunoreactivity (determined by a novel immunoenzyme assay), which was enhanced by thiorphan in both epithelium-free and intact bronchi. (6) These findings suggest that a thiorphan-sensitive mechanism, presumably 'enkephalinase' (endopeptidase 24.11), plays a major role in inactivating endogenous tachykinins released from sensory nerves and that this enzymatic activity is still present after removal of the bronchial epithelium.
Naunyn-Schmiedeberg's Archives of Pharmacology, 1990
1. In the presence of atropine and guanethidine (3 gmol/1 each), electrical field stimulation (1-... more 1. In the presence of atropine and guanethidine (3 gmol/1 each), electrical field stimulation (1-20 Hz) produced frequency-dependent relaxations of the histamine-(3 gmol/1) induced vascular tone in isolated rings from the guinea-pig pulmonary artery. The electricallyevoked relaxations were abolished by tetrodotoxin (1 gmol/1). The amplitude of these nerve-mediated, nonadrenergic non-cholinergic (NANC) relaxations was unaffected by removal of the vascular endothelium produced through rubbing of the internal surface. 2. Capsaicin (1 gmol/1) produced a prompt and sustained relaxation of the histamine-induced tone which was unaffected by removal of the endothelium. A second application of capsaicin 60-120 rain later had no further relaxant effect, indicating desensitization. After in vitro capsaicin desensitization, the electrically-evoked NANC relaxations were abolished, both in the presence or absence of the vascular endothelium. 3. Substance P evoked a prompt and transient relaxation in precontracted arterial rings with intact endothelium and a transient small contraction in rings in which the endothelium had been mechanically removed. The selective NK-I receptor agonist, [Pro9]-substance P sulfone closely mimicked the relaxation produced by substance P while the selective NK-2 or NK-3 receptor agonists had no relaxant effect. Tachyphylaxis to substance P did not modify the amplitude of the capsaicin-induced relaxation. 4. Human alpha calcitonin gene-related peptide (CGRP) produced a prompt and sustained relaxation both in the presence and absence of the vascular endothelium. 5. Ruthenium red (10 gmol/1) blocked the relaxation to capsaicin while leaving unaffected the relaxation to electrical field stimulation or CGRP (0.1 gmol/1). 6. Both substance P (SP)and CGRP-like immunoreactivities (LI) were detected in extracts of the guinea-pig pulmonary artery. Capsaicin (1 gmol/1) evoked a prompt and simultaneous outflow of both SP-and CGRP-LI. A second application of capsaicin 60 rain later failed to increase SP-or CGRP-LI out-Send offprint requests to C. A. Maggi at the above address flow, indicating complete desensitization. A small but clearly detectable release of both SP-LI and CGRP-LI was also evoked by electrical field stimulation. 7. These findings provide evidence that the neurogenic NANC vasodilation in the guinea-pig pulmonary artery is due to antidromic activation of peripheral endings of capsaicinsensitive primary afferents. Endogenous CGRP is a likely mediator for this vasodilation. No evidence was found that endogenous SP might contribute to vasodilation by activating NK-I receptors on endothelial cells.
Journal of Clinical Investigation, 1994
We have previously reported that human eosinophil granule major basic protein and synthetic catio... more We have previously reported that human eosinophil granule major basic protein and synthetic cationic proteins such as poly-L-arginine and poly-L-lysine, can increase airway responsiveness in vivo. In the present study, we have investigated whether activation of sensory C-fibers is important in this phenomenon. Dose-response curves to methacholine were constructed before and 1 h after intratracheal instillation of poly-L-lysine in anaesthetized spontaneously breathing rats, and the concentration of methacholine required to induce a doubling in total lung resistance was calculated. Poly-L-lysine induced a fivefold increase in airway responsiveness, which was inhibited by neonatal capsaicin treatment and potentiated by phosphoramidon (100 jtg/ml). Furthermore, pretreatment with either CP, 96-345, or RP-67580 two selective NK-1 receptor antagonists inhibited poly-L-lysine-induced airway hyperresponsiveness and plasma protein extravasation. In vitro, cationic proteins stimulated the release of calcitonin gene-related peptidelike immunoreactivity from perfused slices of the main bronchi. Our results demonstrate that cationic proteins can activate sensory C-fibers in the airways, an effect which is important in the subsequent development of airway hyperresponsiveness and plasma protein extravasation. Cationic proteins may therefore function as a link between inflammatory cell accumulation and sensory nerve activation. (J.
European Journal of Pharmacology, 1993
The pharmacological actions of the new xanthine, isbufylline, were evaluated in several models of... more The pharmacological actions of the new xanthine, isbufylline, were evaluated in several models of airway hyperresponsiveness and airway inflammation in guinea pigs. At a dose (106 #tool kg-1 i.p.) providing complete protection against acetylcholine aerosol-induced dyspnea in the guinea pig, isbufylline inhibited platelet activating factor (PAF)-and antigen-induced eosinophil infiltration into bronchoalveolar lavage fluid 24 h after challenge of normal and actively immunized guinea pigs, respectively. In addition, this dose of isbufylline also inhibited capsaicin-induced extravasation of protein into bronchoalveolar lavage fluid. Isbufylline, 4.2 /~mol kg-1 i.v., significantly inhibited PAF-induced bronchial hyper-responsiveness to i.v. histamine, without exerting evident bronchodilator activity. On the other hand the bronchodilator, salbutamol, at a dose (10.4 /~mol kg-~ i.p.) shown to be equieffective to isbufylline (106 /zmol kg-1 i.p.) for blocking acetylcholine aerosol-induced dyspnea, had no protective action against PAF-or antigen-induced eosinophil recruitment in bronchoalveolar lavage fluid, or against capsaicin-induced plasma protein extravasation. Furthermore, salbutamol (3.5 #mol kg-~) significantly potentiated allergen-induced cell infiltration and PAF-induced bronchial hyperresponsiveness. The results suggest that isbufylline can exert significant anti-inflammatory actions in guinea pig airways, in addition to its brouchodilator activity. These pharmacological activities are not shared by the/32-adrenoceptor agonist, salbutamoi.
European Journal of Pharmacology, 1988
The effects of intra-and extraluminal capsaicm administration were evaluated in isolated perfused... more The effects of intra-and extraluminal capsaicm administration were evaluated in isolated perfused rat mesentenc bed. Capsalcln (10 nM-1 #M) produced a potent concentration-dependent relaxaUon of the tonic vasoconstriction induced by norepinephrine (1 #M) but not by high-K + (60 mM). The capsaacin-lnduced relaxation was nearly abolished m preparations pretreated in vitro with a high concentration of capsaicm (1 #M, for 10 min, 1 h before). Capsaicin-induced relaxation was reduced but not abolished m preparations obtained from rats pretreated neonatally with capsaicin. The capsaicin effects were unaffected by atropine, guanethidine, propranolol, hexamethonium or tetrodotoxm. The observation that capsaicm (0.1 #M)-induced relaxation was virtually abolished in presence of the proteolytic enzyme a-chymotrypsin (1 U/ml) supports the involvement of neuropepude(s) in this response. Bolus injections of calcitonin gene-related peptide (CGRP) elicited a potent and rapidly ensuing relaxation which underwent tachyphylaxis. However, no cross-desensitization with capsaicin was observed. It ~s concluded that activation of capsaicin-sensitive sensory fibers could release neuropeptides locally with a potent effect on intestinal blood flow.
European Journal of Pharmacology, 1995
The antibronchospastic activity against acetylcholine, antigen, histamine plus platelet-activatin... more The antibronchospastic activity against acetylcholine, antigen, histamine plus platelet-activating factor (PAF) or the selective tachykinin neurokinin (NK) 1 and NK 2 receptor agonists of the novel tachykinin NK 2 receptor antagonist, MEN10,627 (cyclo(Met-Asp-Trp-Phe-Dap-Leu)cyclo(2/3-5/3)), was studied in anesthetized guinea-pigs. MEN10,627 (30-100 nmol/kg i.v.) reduced in a dose-dependent manner the bronchospasm induced by the tachykinin NK 2 receptor agonist [/3AlaS]neurokinin A-(4-10) and the effect of the highest dose lasted up to 5 h from its administration. Conversely, airway constriction induced by the NK l receptor agonist [Sar9]substance P sulfone or acetylcholine was unaffected by MEN10,627 up to a dose of 3 tzmol/kg i.v. In animals sensitized with ovalbumin and pretreated with the endopeptidase inhibitor phosphoramidon, the aerosolized antigen produced a bronchospasm which was inhibited by MEN10,627 (30-100 nmol/kg i.v.) but not by the tachykinin NK 1 receptor antagonist, (+)-CP96,345 ([2R,3R-cisand [2S,3S)-cis-2-(diphenylmethyl)-N-[(2-methoxyphenyl)-methyl]-lazabicyclo[2.2.2]octan-3-amine]) (3 tzmol/kg i.v.). Both MEN10,627 (30-100 nmol/kg i.v.) and (_+)-CP96,345 (30-300 nmol/kg i.v.) reduced the PAF-induced hyperresponsiveness to histamine, without affecting the hypotension induced by PAF or the bronchospasm induced by histamine in guinea-pigs not exposed to PAF, showing the involvement of both tachykinin NK 1 and NK 2 receptors in this model. In summary, MEN10,627 behaves as a potent, selective and long-lasting tachykinin NK 2 receptor antagonist in vivo. Further, tachykinin NK 2 receptors could be activated during allergic responses and in the development of airway hyperresponsiveness.
Drug Development Research, 1991
In vitro and in vivo studies on the effects of the alpha-adrenoceptor blocker IPi66 (1-(2-ethoxy-... more In vitro and in vivo studies on the effects of the alpha-adrenoceptor blocker IPi66 (1-(2-ethoxy-2-(3'-pyridyl)ethyl)-4-(2'-methoxy-phenyl)piperazine) on urethral tone in rats. Drug Dev. Res. 23: 35-46, 1991. IP/66 (1-(2-ethoxy-2-(3'-pyridyl)ethyl)-4-(2'-methoxy-phenyl)piperazine is a newly synthetized and stereoselective alpha-adrenoceptor blocking drug. This compound exhibits preferential blocking activity in postjunctional as compared to prejunctional alpha-adrenergic responses. Furthermore, IP/66 inhibits phenylephrine-induced motor response in human and rat prostatic tissue and phenylephrine-, DMPP-and EFS-induced motor responses in rat urethral tissues, being equieffective or even more potent than prazosin. Like prazosin, intravenous administration of IP/66, at doses at which no hypotensive effect is observed, induces a marked inhibition of phenylephrine or DMPP-induced increase in urethral perfusion pressure, in anaesthetized pithed rats. Finally, IP/66 administration exerts beneficial effects in animals with surgically-or pharmacologically-induced urethral outflow obstruction.
British Journal of Pharmacology, 1989
Bradykinin and capsaicin were compared for their ability to elicit functional effects and to rele... more Bradykinin and capsaicin were compared for their ability to elicit functional effects and to release sensory neuropeptides from guinea-pig isolated perfused hearts. 2 Both bradykinin (1O/M) and capsaicin (1 pM) produced a marked increase in coronary flow, a large positive chronotropic effect and a significant reduction in contractile strength. These actions were associated with a marked release of substance P-like immunoreactivity (SP-LI) and calcitonin gene-related-like immunoreactivity (CGRP-LI). The percentage of the tissue content of SP-LI and CGRP-LI released by each agent was similar, although bradykinin was less effective than capsaicin. The ratio of SP-LI/CGRP-LI released by both agents was similar to that present in cardiac tissue. 3 Neuropeptide release could be evoked only once with capsaicin but at least four times with bradykinin. Also, functional responses to capsaicin underwent desensitization. After either in vitro or systemic capsaicin pretreatment, the release of SP-LI and CGRP-LI by bradykinin was reduced and the positive chronotropic effect of bradykinin was significantly reduced, while the increase in coronary flow and negative inotropic responses remained unchanged. 4 Pretreatment with indomethacin (10/M) strongly antagonized the release of SP-LI and CGRP-LI by bradykinin and reduced the increase in heart rate. 5 These findings suggest that activation by bradykinin (probably through indirect mechanisms) of capsaicin-sensitive sensory nerves in the heart, leads to a local release of sensory neuropeptides. These neuropeptides, in turn, could participate in determining the complex functional effects of this kinin on cardiac performance.
British Journal of Pharmacology, 1988
Both bradykinin and capsaicin infusion evoked a marked increase in the outflow of substance P-(SP... more Both bradykinin and capsaicin infusion evoked a marked increase in the outflow of substance P-(SP-LI) and calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) from guinea-pig isolated, perfused heart. After acute exposure to capsaicin in vitro, or in hearts taken from animals pretreated in vivo with capsaicin, bradykinin failed to induce any release. The positive chronotropic effect of bradykinin was reduced after acute capsaicin administration. The effect of bradykinin in the guinea-pig heart could be mediated, at least partly, by release of neuropeptides from peripheral endings of capsaicin-sensitive sensory neurones.
British Journal of Pharmacology, 1989
Administration of arachidonic acid (AA) both in vitro and in vivo elicited prominent contractile ... more Administration of arachidonic acid (AA) both in vitro and in vivo elicited prominent contractile responses in guinea-pig airways, which were markedly reduced after capsaicin desensitization. Furthermore, AA superfusion elicited a significant calcitonin gene-related peptide-like immunoreactivity release from isolated bronchi. It is suggested that at least part of the bronchomotor actions of AA rely upon stimulation of capsaicinsensitive primary afferents.
Journal of Autonomic Pharmacology, 1992
Intravenous administration of substance P (SP) or of the NK, selective agonist [P-Ala4, Sar9, Met... more Intravenous administration of substance P (SP) or of the NK, selective agonist [P-Ala4, Sar9, Met (O,)ll] SP-(4-1 I) increased vascular permeability in the urinary bladder of urethane-anaesthetized rats, providing evidence for an NK, receptor-mediated inflammatory response. 2. BW 755C, a dual inhibitor of arachidonate cyclo-oxygenase and lipoxygenase, significantly reduced the plasma extravasation induced by SP, but did not modify the effect of v-Ala4, Sar9, Met (0,)11] SP-(4-1 1). 3 SP-induced microvascular leakage was also inhibited by systemic pretreatment with indomethacin or with the prostaglandin receptor antagonist SC-19220, while it was unaffected by the selective 5-lipoxygenase inhibitor BW A4C or the leukotriene antagonist FPL 557 12. 4 Pretreatment of rats with the mast cell degranulating agent compound 48/80 significantly attenuated the inflammatory effect of SP. Indomethacin administration to 48/80-pretreated animals failed to produce further inhibition. 5 These findings indicate that intravascular SP promotes plasma exudation in rat urinary bladder through an NK,-mediated effect on venular permeability and the release of cyclo-oxygenase metabolites of arachidonic acid. The latter effect largely derives from the interaction of the neuropeptide with mast cells.