J.-c. Stoclet | Université de Strasbourg (original) (raw)
Papers by J.-c. Stoclet
British Journal of Pharmacology, 1985
The possible modulation by endothelium of phenylephreine-and prostaglandin F2,-induced mobilizati... more The possible modulation by endothelium of phenylephreine-and prostaglandin F2,-induced mobilization of calcium for contraction in the rat aorta has been investigated. Contractions elicited by these and other agonists are inhibited in the presence of endothelium.
Artery, 1980
The activities of cyclic AMP- and cyclic GMP-phosphodiesterase were studied in the aorta (freed o... more The activities of cyclic AMP- and cyclic GMP-phosphodiesterase were studied in the aorta (freed of the adventitia layer) of spontaneously hypertensive rats (SHRs). At the time of weaning (3 weeks of age) young SHRs were separated into two groups. One group was chronically treated with propranolol, 50 mg.kg-1 daily for 4 weeks (treated rats), with treatement beginning either at the time of weaning or at 15 weeks of age. The second group (non-treated SHRs) was used as control. In both groups we observed that the protein content per aorta but not the DNA content increased parallel to the organ weight. The enzyme activities were related to the DNA content of aorta. In non-treated SHRs, the phosphodiesterase activties increased with age, but there was a considerable lag of time between the marked increase in blood pressure that occured between 5 and 12 weeks of age and the increase in phosphodiesterase activity which started after 12 weeks of age. Prolonged propranolol treatment signific...
Journal de physiologie, 1970
Comptes rendus des séances de la Société de biologie et de ses filiales, 1973
Comptes rendus des séances de la Société de biologie et de ses filiales, 1970
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](Neurochemistry International, 1991
Journal of Pharmacy and Pharmacology, 1980
when compared with rats injected acutely with saline. Since the apomorphine-induced sedation is c... more when compared with rats injected acutely with saline. Since the apomorphine-induced sedation is considered to be mediated by presynaptic dopamine receptors, these data are evidence for the development of presynaptic supersensitivity following chronic haloperidol. Higher doses of apomorphine elevated locomotor activity to presedative levels indicating an activation of supersensitive postsynaptic dopamine receptors. In addition 2 out of 5 rats displayed obvious stereotypic behaviour. Combined injection of haloperidol and lithium daily for 34 days reversed the preand postsynaptic supersensitive responses to apomorphine. Apomorphine at 0.004 and 0.008 mg kg-' did not induce significant inhibition of locomotor activity as was seen in rats treated chronically with only haloperidol (Fig. 1). This supports previous electrophysiological data suggesting that lithium blocks the development of presynaptic dopamine receptor supersensitivity. The higher doses of apomorphine did not produce increases in locomotor activity in chronic haloperidol plus lithium treated rats (Fig. 1). On the contrary apomorphine (0.01 6 mg kg-l) induced sedation that was analogous to the responses seen in the control groups. In conclusion lithium appears to block the develop. ment of supersensitivity in both preand postsynaptic dopamine receptors. The chronic lithium regimen has been demonstrated to result in plasma lithium concen. trations in the therapeutic range of lithium in man (Allikments et al 1979). Therefore the stabilization of preand postsynaptic receptors by lithium may repre. sent an important mechanism in the clinical pharmacotherapy of manic-depressive disorders and tardive dyskinesia. February 1 , 1980
Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 1999
Epidemiological studies have suggested that moderate consumption of red wine might reduce the ris... more Epidemiological studies have suggested that moderate consumption of red wine might reduce the risk of cardiovascular disease. Red Wine Polyphenolic Compounds (RWPC), a complex extract obtained from red wine, causes endothelium-dependent vasorelaxation in rat aortic rings pre-contracted with noradrenaline. This effect is associated with marked formation of NO in the vessel (directly shown by electron paramagnetic resonance spectroscopy) and it is abolished by the NO synthase inhibitor N(G)-nitro-L-arginine methylester (300 microM). It is mimicked by some defined polyphenols (like the anthocyanin delphinidin) but not by others (malvidin, cyanidin, quercetin, catechin, epicatechin), despite close structures. In addition, RWPC causes an extracellular Ca(2+)-dependent increase in [Ca2+]i in endothelial but not in smooth muscle cells. The efficiency of RWPC in inducing NO production in the aorta and increase in [Ca2+]i, in endothelial cells is comparable to those of carbachol and bradykin...
Physiological Research, 2004
Diaphorase was studied as a possible oxidoreductase participating in NO production from some vaso... more Diaphorase was studied as a possible oxidoreductase participating in NO production from some vasorelaxants. In the presence of NADH or NADPH, diaphorase can convert selected NO donors, glycerol trinitrate (GTN) and formaldoxime (FAL) to nitrites and nitrates with NO as an intermediate. This activity of diaphorase was inhibited by diphenyleneiodonium (DPI) (inhibitor of some NADPH-dependent flavoprotein oxidoreductases), while it remained uninhibited by NG-nitro-L-arginine methyl ester (inhibitor of NO synthase) 7-Ethoxyresorufin (inhibitor of cytochrome P-450 1A1 and cytochrome P-450 NADPH-dependent reductase) inhibited the conversion of GTN only. Existence of NO as an intermediate of the reaction was supported by results of electron paramagnetic resonance spectroscopy. In addition to its ability to affect the above mentioned NO donors, diaphorase was able to reduce 2-phenyl-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) and thus to eliminate its NO scavenging effect. This ac...
Laboratory investigation; a journal of technical methods and pathology, 1987
Morphological changes of aortic myocytes grown in primary cultures on collagen gels, were induced... more Morphological changes of aortic myocytes grown in primary cultures on collagen gels, were induced by two adrenergic agonists, in the absence or presence of specific antagonists. Their effects were quantified by means of the measurement of the surface areas of the images of the cells. The alpha-adrenoreceptor agonist phenylephrine induced a concentration-dependent decrease of the surface areas of the images of the cells, which was competitively antagonized by phentolamine, and was reduced in the presence of CdCl2 (an inhibitor of calcium entry). The beta-adrenoreceptor agonist isoproterenol induced an increase in the surface areas of the images of prostaglandin F2-alpha pretreated cells and this effect was antagonized by propranolol. It is concluded that the morphological changes of myocytes in primary culture, induced by phenylephrine or isoproterenol can be quantified by the measurement of the surface areas of their images. These changes were in good agreement with the response of ...
Naunyn-Schmiedeberg's archives of pharmacology, 1990
Experiments were designed to evaluate the effect of cyclic AMP on the electrically-induced releas... more Experiments were designed to evaluate the effect of cyclic AMP on the electrically-induced release of noradrenaline from vascular sympathetic nerve terminals. The possible implication of the inhibition of adenylate cyclase in the negative feed-back control by prejunctional alpha 2-adrenoceptors of neurotransmitter release was also investigated. Rat isolated tail arteries were preincubated with [3H]-noradrenaline; the preparations were subsequently perfused/superfused with [3H )-noradrenaline-free medium and their perivascular nerves were field stimulated with 24 pulses at 0.4 Hz (0.3 ms, 200 mA). 2 compounds known to enhance the intracellular concentration of cyclic AMP, namely the membrane permeant analogue 8-Br-cAMP (10-300 mumol/l) and forskolin (0.3-10 mumol/l), an activator of adenylate cyclase, concentration-dependently enhanced the stimulation-evoked tritium overflow. The 1,9-dideoxy derivative of forskolin, which does not stimulate adenylate cyclase, was ineffective. Exposur...
Vascular Smooth Muscle / Der Gefäßmuskel, 1972
The successive phases of tension development and relaxation were investigated on helical strips o... more The successive phases of tension development and relaxation were investigated on helical strips of thoracic aorta. Maximal isometric responses were elicited by noradrenaline (NA) and BaCl2 in normal or Ca-free Krebs-bicarbonate solution (PSS). They were either potentiated by pretreatment in vivo with reserpine (Re, 5 mg/kg, i.p., 24 h) or depressed by addition of N-2′ -0 dibutyryl-adenosine 3′ 5′ monophosphate (cAMP, 1 × 10−7M) or Papaverine (Pp., 0.5 × 10−5M) in the PSS.
British Journal of Pharmacology, 1985
The possible modulation by endothelium of phenylephreine-and prostaglandin F2,-induced mobilizati... more The possible modulation by endothelium of phenylephreine-and prostaglandin F2,-induced mobilization of calcium for contraction in the rat aorta has been investigated. Contractions elicited by these and other agonists are inhibited in the presence of endothelium.
Artery, 1980
The activities of cyclic AMP- and cyclic GMP-phosphodiesterase were studied in the aorta (freed o... more The activities of cyclic AMP- and cyclic GMP-phosphodiesterase were studied in the aorta (freed of the adventitia layer) of spontaneously hypertensive rats (SHRs). At the time of weaning (3 weeks of age) young SHRs were separated into two groups. One group was chronically treated with propranolol, 50 mg.kg-1 daily for 4 weeks (treated rats), with treatement beginning either at the time of weaning or at 15 weeks of age. The second group (non-treated SHRs) was used as control. In both groups we observed that the protein content per aorta but not the DNA content increased parallel to the organ weight. The enzyme activities were related to the DNA content of aorta. In non-treated SHRs, the phosphodiesterase activties increased with age, but there was a considerable lag of time between the marked increase in blood pressure that occured between 5 and 12 weeks of age and the increase in phosphodiesterase activity which started after 12 weeks of age. Prolonged propranolol treatment signific...
Journal de physiologie, 1970
Comptes rendus des séances de la Société de biologie et de ses filiales, 1973
Comptes rendus des séances de la Société de biologie et de ses filiales, 1970
Neurochemistry International, 1991
Journal of Pharmacy and Pharmacology, 1980
when compared with rats injected acutely with saline. Since the apomorphine-induced sedation is c... more when compared with rats injected acutely with saline. Since the apomorphine-induced sedation is considered to be mediated by presynaptic dopamine receptors, these data are evidence for the development of presynaptic supersensitivity following chronic haloperidol. Higher doses of apomorphine elevated locomotor activity to presedative levels indicating an activation of supersensitive postsynaptic dopamine receptors. In addition 2 out of 5 rats displayed obvious stereotypic behaviour. Combined injection of haloperidol and lithium daily for 34 days reversed the preand postsynaptic supersensitive responses to apomorphine. Apomorphine at 0.004 and 0.008 mg kg-' did not induce significant inhibition of locomotor activity as was seen in rats treated chronically with only haloperidol (Fig. 1). This supports previous electrophysiological data suggesting that lithium blocks the development of presynaptic dopamine receptor supersensitivity. The higher doses of apomorphine did not produce increases in locomotor activity in chronic haloperidol plus lithium treated rats (Fig. 1). On the contrary apomorphine (0.01 6 mg kg-l) induced sedation that was analogous to the responses seen in the control groups. In conclusion lithium appears to block the develop. ment of supersensitivity in both preand postsynaptic dopamine receptors. The chronic lithium regimen has been demonstrated to result in plasma lithium concen. trations in the therapeutic range of lithium in man (Allikments et al 1979). Therefore the stabilization of preand postsynaptic receptors by lithium may repre. sent an important mechanism in the clinical pharmacotherapy of manic-depressive disorders and tardive dyskinesia. February 1 , 1980
Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 1999
Epidemiological studies have suggested that moderate consumption of red wine might reduce the ris... more Epidemiological studies have suggested that moderate consumption of red wine might reduce the risk of cardiovascular disease. Red Wine Polyphenolic Compounds (RWPC), a complex extract obtained from red wine, causes endothelium-dependent vasorelaxation in rat aortic rings pre-contracted with noradrenaline. This effect is associated with marked formation of NO in the vessel (directly shown by electron paramagnetic resonance spectroscopy) and it is abolished by the NO synthase inhibitor N(G)-nitro-L-arginine methylester (300 microM). It is mimicked by some defined polyphenols (like the anthocyanin delphinidin) but not by others (malvidin, cyanidin, quercetin, catechin, epicatechin), despite close structures. In addition, RWPC causes an extracellular Ca(2+)-dependent increase in [Ca2+]i in endothelial but not in smooth muscle cells. The efficiency of RWPC in inducing NO production in the aorta and increase in [Ca2+]i, in endothelial cells is comparable to those of carbachol and bradykin...
Physiological Research, 2004
Diaphorase was studied as a possible oxidoreductase participating in NO production from some vaso... more Diaphorase was studied as a possible oxidoreductase participating in NO production from some vasorelaxants. In the presence of NADH or NADPH, diaphorase can convert selected NO donors, glycerol trinitrate (GTN) and formaldoxime (FAL) to nitrites and nitrates with NO as an intermediate. This activity of diaphorase was inhibited by diphenyleneiodonium (DPI) (inhibitor of some NADPH-dependent flavoprotein oxidoreductases), while it remained uninhibited by NG-nitro-L-arginine methyl ester (inhibitor of NO synthase) 7-Ethoxyresorufin (inhibitor of cytochrome P-450 1A1 and cytochrome P-450 NADPH-dependent reductase) inhibited the conversion of GTN only. Existence of NO as an intermediate of the reaction was supported by results of electron paramagnetic resonance spectroscopy. In addition to its ability to affect the above mentioned NO donors, diaphorase was able to reduce 2-phenyl-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) and thus to eliminate its NO scavenging effect. This ac...
Laboratory investigation; a journal of technical methods and pathology, 1987
Morphological changes of aortic myocytes grown in primary cultures on collagen gels, were induced... more Morphological changes of aortic myocytes grown in primary cultures on collagen gels, were induced by two adrenergic agonists, in the absence or presence of specific antagonists. Their effects were quantified by means of the measurement of the surface areas of the images of the cells. The alpha-adrenoreceptor agonist phenylephrine induced a concentration-dependent decrease of the surface areas of the images of the cells, which was competitively antagonized by phentolamine, and was reduced in the presence of CdCl2 (an inhibitor of calcium entry). The beta-adrenoreceptor agonist isoproterenol induced an increase in the surface areas of the images of prostaglandin F2-alpha pretreated cells and this effect was antagonized by propranolol. It is concluded that the morphological changes of myocytes in primary culture, induced by phenylephrine or isoproterenol can be quantified by the measurement of the surface areas of their images. These changes were in good agreement with the response of ...
Naunyn-Schmiedeberg's archives of pharmacology, 1990
Experiments were designed to evaluate the effect of cyclic AMP on the electrically-induced releas... more Experiments were designed to evaluate the effect of cyclic AMP on the electrically-induced release of noradrenaline from vascular sympathetic nerve terminals. The possible implication of the inhibition of adenylate cyclase in the negative feed-back control by prejunctional alpha 2-adrenoceptors of neurotransmitter release was also investigated. Rat isolated tail arteries were preincubated with [3H]-noradrenaline; the preparations were subsequently perfused/superfused with [3H )-noradrenaline-free medium and their perivascular nerves were field stimulated with 24 pulses at 0.4 Hz (0.3 ms, 200 mA). 2 compounds known to enhance the intracellular concentration of cyclic AMP, namely the membrane permeant analogue 8-Br-cAMP (10-300 mumol/l) and forskolin (0.3-10 mumol/l), an activator of adenylate cyclase, concentration-dependently enhanced the stimulation-evoked tritium overflow. The 1,9-dideoxy derivative of forskolin, which does not stimulate adenylate cyclase, was ineffective. Exposur...
Vascular Smooth Muscle / Der Gefäßmuskel, 1972
The successive phases of tension development and relaxation were investigated on helical strips o... more The successive phases of tension development and relaxation were investigated on helical strips of thoracic aorta. Maximal isometric responses were elicited by noradrenaline (NA) and BaCl2 in normal or Ca-free Krebs-bicarbonate solution (PSS). They were either potentiated by pretreatment in vivo with reserpine (Re, 5 mg/kg, i.p., 24 h) or depressed by addition of N-2′ -0 dibutyryl-adenosine 3′ 5′ monophosphate (cAMP, 1 × 10−7M) or Papaverine (Pp., 0.5 × 10−5M) in the PSS.