Alejandro Esteller - Academia.edu (original) (raw)
Papers by Alejandro Esteller
Comparative Biochemistry and Physiology Part A: Physiology, 1977
Some aspects of the exocrine pancreatic secretion in two species of primates, (E. putas and P. ma... more Some aspects of the exocrine pancreatic secretion in two species of primates, (E. putas and P. mandrillus), have been investigated. 2. The resting flow in P. mandrillus was high and contained a low concentration of amylase. There was no resting secretion in E. patas. 3. Intravenous infusions of secretin increased the flow of pancreatic juice in both species, the monkeys being highly sensitive to the hormone. In E. patas single injection or infusions of PZ-CCK increased the flow and amylase content of the juice. 4. Stimulation of the cervical vagus nerves increased the flow and amylase content of the juice in both species; there were quite wide differences between individuals of the same species as well as between species. Atropine reduced, but did not abolish the pancreatic response caused by vagal stimulation. 5. In E. patas the concentration of chloride ions fell when the flow of juice increased; in P. mandrillus remained constant at different rates of flow. 6. The present experiments show that even between related primate species quite substantial differences in the properties of the exocrine pancreas may occur.
Revista española de fisiología, 1975
The bile salts, chloride, sodium, potassium and nitrogen content of the gallbladder bile was stud... more The bile salts, chloride, sodium, potassium and nitrogen content of the gallbladder bile was studied in goat, sheep, cattle, pig, rabbit, dog, monkey (Erythrocebus patas), chicken, lizard (Lacerta ocellata), frog (Rana esculenta), trout (Salmo gardnieri) and barbel (Barbus barbus). A significant correlation was found between bile salts and sodium (positive), chloride and sodium (negative) and chloride and bile salts (negative). The gallbladder concentrating ability was very high in monkey, lizard and trout high in dog, barbel, frog and chicken, and low in cattle, rabbit, pig and sheep. The goat was half way between the second and third groups. It seems that concentrating ability is greater in animals whose gastric emptying is intermittent, and is lower in those animals with a continuous digestive activity.
the rabbit Effect of pentobarbital or urethane on bile secretion and chemical composition of bloo... more the rabbit Effect of pentobarbital or urethane on bile secretion and chemical composition of blood in
Revista espanola de fisiologia, 1977
Stimulation of the thoracic vagus nerves in anesthetized rabbit appears to act only by increasing... more Stimulation of the thoracic vagus nerves in anesthetized rabbit appears to act only by increasing the amylase content of pancreatic juice. Stimulation of the abdominal vagus nerve slightly increased the flow of juice and clearly its amylase content, effects which were respectively reduced and abolished by atropine. The vagal control of the exocrine pancreas in rabbits shows substantial differences when compared with other herbivorous monogastric species such as horse and pig.
Clinical Science, 1984
1. The interference between biliary phospholipid and bilirubin secretion was investigated in rats... more 1. The interference between biliary phospholipid and bilirubin secretion was investigated in rats with bile fistulae, under conditions of normal and maximal bilirubin secretion. The enterohepatic circulation of bile salts was interrupted and the animals received infusions of sodium taurocholate, a micelle-forming physiological bile salt. 2. Sodium taurocholate infusion (0.19 μmol min−1 100 g−1 body weight) induced an increase in bile flow and phospholipid secretion, while basal bilirubin secretion was not increased. 3. Bilirubin infusion (0.26 μmol min−1 100 g−1 body weight) induced a decrease in basal and taurocholate-stimulated phospholipid secretion. Biliary mixed micelle formation was presumably altered during bilirubin infusion, although bile taurocholate concentration, taurocholate secretion rate and bile flow were not modified. 4. When sodium taurocholate was infused during bilirubin-decreased phospholipid secretion, this secretion was restored but maximal biliary bilirubin s...
Comparative Biochemistry and Physiology Part A: Physiology, 1979
The effects which experimental hypothermia induces on rabbit and rat biliary secretion have been ... more The effects which experimental hypothermia induces on rabbit and rat biliary secretion have been investigated. 2. In both species we have found a drastic reduction in bile-flow and in bile salt output and an increase in bile-salt concentration. 3. Hypothermia induces a substantial decrease of bile salt independent fraction (BSIF) in both rabbit (80%) and rat (70%) which we believe may be due to a loss of activity of Na+, K+-activated ATPase. 4. Rewarming is not able to reverse the negative effect that hypothermia has on rabbit bile flow.
Revista española de fisiología, 1983
The biliary secretion in response to food has been studied in chicken. In this species, a well de... more The biliary secretion in response to food has been studied in chicken. In this species, a well defined biliary postprandial response with a clear vesicular component can be estimated. The bile salt independent fraction increases after feeding. Our results show that gallbladder bile has a lower osmotic power. The biliary response to food when the enterohepatic circulation is blocked, diminishes. The relationship between bile salt independent fraction values, whether the vesicular duct is tied or not, remains constant when the enterohepatic circulation is interrupted.
Physiologia Bohemoslovaca, 1985
Basal exocrine pancreatic secretion was studied in anaesthetized and conscious chickens and spont... more Basal exocrine pancreatic secretion was studied in anaesthetized and conscious chickens and spontaneous secretion was studied in anaesthetized chickens. Results are compared with those of other vertebrates to estimate the specific pattern of this secretion in birds. The flow of pancreatic juice was greater in conscious chickens than when anaesthetized (Table 1). Amylase activity was greater than that of the other species and was of the same order in anaesthetized and conscious birds (Table 1). A spontaneous exocrine pancreatic secretion was seen to remain after eliminating a large part of the tonic influences (Table 2).
Comparative Biochemistry and Physiology Part A: Physiology, 1981
... Dl;roNi J. .1. HHN & S(RAT(HI,RI> T. (1974) Further evi-dence that secretin stimulates... more ... Dl;roNi J. .1. HHN & S(RAT(HI,RI> T. (1974) Further evi-dence that secretin stimulates pancreatic secretion through adenosine 3'-5'-monophosphatc (c-AMP). ,/. ... 200,478. WAELE B.. DESMUL A.. WISSOCQ P. & LIEKENS R. (1974) La secretion pancr atique chez le rat. ...
Quarterly Journal of Experimental Physiology, 1981
The biliary response to feeding has been investigated in intact and cholecystectomized rabbits, w... more The biliary response to feeding has been investigated in intact and cholecystectomized rabbits, with and without interruption of the enterohepatic circulation of bile salts. The relative contribution of the different secretory mechanisms involved in this process has been examined. Feeding induced an increase in the flow and bicarbonate concentration of the bile and a slight decrease in the bile salt content in rabbits with gall bladders and the enterohepatic circulation intact. Feeding with the enterohepatic circulation interrupted elicited a drop in bile flow and the bile salt concentration, but an increase in bicarbonate concentration. Interruption of the enterohepatic circulation thus dramatically modifies the feeding response: a response to food is still detectable after interruption, but is masked by the negative effects of drainage of the bile away from the duodenum.
Quarterly Journal of Experimental Physiology, 1981
The role of enterohepatic circulation of bile salts in biliary secretion in conscious rabbits has... more The role of enterohepatic circulation of bile salts in biliary secretion in conscious rabbits has been investigated before and after cholecystectomy. Bile flow was higher and bile salt concentration lower in cholecystectomized than in intact rabbits: this could have been caused by a negative feedback effect on bile salt synthesis as the circulating bile salt pool increased. The effects of cholecystectomy on flow and bile salt concentration balanced each other. Bile flow and bile salt concentration declined after interruption of the enterohepatic circulation in both cholecystectomized and intact rabbits. Furthermore, the percentage of the flow of bile independent of bile salt secretion increased, while that independent of total analysed solutes decreased after the enterohepatic circulation was broken. These results confirm that the decrease in bile flow after interruption of the enterohepatic circulation is due to loss of bile salts and not of electrolytes. * See Methods.
The Open Gastroenterology Journal, 2011
European Journal of Pharmacology, 2007
We examined the ability of the flavonoids quercetin and kaempferol to modulate inducible nitric o... more We examined the ability of the flavonoids quercetin and kaempferol to modulate inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and reactive C-protein (CRP) expression, and to induce changes in the nuclear factor kappa B (NF-κB) pathway in the human hepatocyte-derived cell line Chang Liver. Cells were incubated with a cytokine mixture supplemented with quercetin or kaempferol (5 to 200 μmol/l). Kaempferol produced a significant concentration-dependent decrease of iNOS, COX-2 and CRP protein level at all concentrations, but the percentage of inhibition induced by quercetin was reduced at high concentrations. Both flavonoids significantly inhibited mRNA level of iNOS, COX-2, and CRP. Inhibitory effects by quercetin and kaempferol were also observed on NF-κB activation and on protein concentration of the phosphorylated form of the inhibitor IκBα and of IKK (IκB kinase)α. The present study suggests that the modulation of iNOS, COX-2 and CRP by quercetin or kaempferol may contribute to the anti-inflammatory effects of these two structurally similar flavonoids in Chang Liver cells, via mechanisms likely to involve blockade of NF-κB activation and the resultant up-regulation of the pro-inflammatory genes. Our data also indicate that the minor structural differences between both compounds determine differences in their inhibitory capacity.
Publisher Summary This chapter describes the effect of bile salts on the excretion of bilirubin b... more Publisher Summary This chapter describes the effect of bile salts on the excretion of bilirubin by the rabbit. It describes an experiment in which animals were anaesthetized with pentobarbital sodium intravenously. A catheter was placed in the left femoral vein for administration of fluids. The cystic duct was ligated and a catheter was placed in the common duct. Rectal temperature was maintained at 38.5°C ± 0.5°C on a heating table. After an equilibrium period of 30 min, an infusion of bilirubin was initiated at a rate of 0.6 mg/kg body wt/min (period A). This rate was chosen because higher rates do not result in an increase of maximal excretion whose value was 0.94 μEq/kg body wt/min similar to those previously reported in the rat, sheep, and rhesus monkey. An hour later, a simultaneous bile salt infusion was given for 60 min at a rate of 0.9 mg/kg body wt/min (period B). Two micelle forming salts, namely, glycodeoxycholate and taurocholate, and one synthetic salt not forming micelles in vitro , that is, dehydrocholate, were tested. It was found that the three bile salts have a similar effect on the maximal excretion of bilirubin.
British Journal of Experimental Pathology, Dec 1, 1987
Biliary calcium secretion during liver regeneration following two-thirds hepatectomy was studied ... more Biliary calcium secretion during liver regeneration following two-thirds hepatectomy was studied in Wistar rats. Calcium output per Ioo g body weight was significantly reduced at 24 h post-hepatectomy but not at other times. Values per gram of liver were significantly increased at 48 h and 96 h. A significant relationship was found between bile acid output and calcium output into bile both in controls and hepatectomized animals. The number of nmol of calcium secreted per nmol of bile acids was increased at 24 h post-hepatectomy parallel to an increased choleretic capacity of bile acids and a decrease in the fraction of bile acid independent flow. Our data confirm that bile acid secretion is an important determinant in the secretion of calcium into bile after partial hepatectomy in the rat.
Comparative Biochemistry and Physiology Part A: Physiology, 1977
Some aspects of the exocrine pancreatic secretion in two species of primates, (E. putas and P. ma... more Some aspects of the exocrine pancreatic secretion in two species of primates, (E. putas and P. mandrillus), have been investigated. 2. The resting flow in P. mandrillus was high and contained a low concentration of amylase. There was no resting secretion in E. patas. 3. Intravenous infusions of secretin increased the flow of pancreatic juice in both species, the monkeys being highly sensitive to the hormone. In E. patas single injection or infusions of PZ-CCK increased the flow and amylase content of the juice. 4. Stimulation of the cervical vagus nerves increased the flow and amylase content of the juice in both species; there were quite wide differences between individuals of the same species as well as between species. Atropine reduced, but did not abolish the pancreatic response caused by vagal stimulation. 5. In E. patas the concentration of chloride ions fell when the flow of juice increased; in P. mandrillus remained constant at different rates of flow. 6. The present experiments show that even between related primate species quite substantial differences in the properties of the exocrine pancreas may occur.
Revista española de fisiología, 1975
The bile salts, chloride, sodium, potassium and nitrogen content of the gallbladder bile was stud... more The bile salts, chloride, sodium, potassium and nitrogen content of the gallbladder bile was studied in goat, sheep, cattle, pig, rabbit, dog, monkey (Erythrocebus patas), chicken, lizard (Lacerta ocellata), frog (Rana esculenta), trout (Salmo gardnieri) and barbel (Barbus barbus). A significant correlation was found between bile salts and sodium (positive), chloride and sodium (negative) and chloride and bile salts (negative). The gallbladder concentrating ability was very high in monkey, lizard and trout high in dog, barbel, frog and chicken, and low in cattle, rabbit, pig and sheep. The goat was half way between the second and third groups. It seems that concentrating ability is greater in animals whose gastric emptying is intermittent, and is lower in those animals with a continuous digestive activity.
the rabbit Effect of pentobarbital or urethane on bile secretion and chemical composition of bloo... more the rabbit Effect of pentobarbital or urethane on bile secretion and chemical composition of blood in
Revista espanola de fisiologia, 1977
Stimulation of the thoracic vagus nerves in anesthetized rabbit appears to act only by increasing... more Stimulation of the thoracic vagus nerves in anesthetized rabbit appears to act only by increasing the amylase content of pancreatic juice. Stimulation of the abdominal vagus nerve slightly increased the flow of juice and clearly its amylase content, effects which were respectively reduced and abolished by atropine. The vagal control of the exocrine pancreas in rabbits shows substantial differences when compared with other herbivorous monogastric species such as horse and pig.
Clinical Science, 1984
1. The interference between biliary phospholipid and bilirubin secretion was investigated in rats... more 1. The interference between biliary phospholipid and bilirubin secretion was investigated in rats with bile fistulae, under conditions of normal and maximal bilirubin secretion. The enterohepatic circulation of bile salts was interrupted and the animals received infusions of sodium taurocholate, a micelle-forming physiological bile salt. 2. Sodium taurocholate infusion (0.19 μmol min−1 100 g−1 body weight) induced an increase in bile flow and phospholipid secretion, while basal bilirubin secretion was not increased. 3. Bilirubin infusion (0.26 μmol min−1 100 g−1 body weight) induced a decrease in basal and taurocholate-stimulated phospholipid secretion. Biliary mixed micelle formation was presumably altered during bilirubin infusion, although bile taurocholate concentration, taurocholate secretion rate and bile flow were not modified. 4. When sodium taurocholate was infused during bilirubin-decreased phospholipid secretion, this secretion was restored but maximal biliary bilirubin s...
Comparative Biochemistry and Physiology Part A: Physiology, 1979
The effects which experimental hypothermia induces on rabbit and rat biliary secretion have been ... more The effects which experimental hypothermia induces on rabbit and rat biliary secretion have been investigated. 2. In both species we have found a drastic reduction in bile-flow and in bile salt output and an increase in bile-salt concentration. 3. Hypothermia induces a substantial decrease of bile salt independent fraction (BSIF) in both rabbit (80%) and rat (70%) which we believe may be due to a loss of activity of Na+, K+-activated ATPase. 4. Rewarming is not able to reverse the negative effect that hypothermia has on rabbit bile flow.
Revista española de fisiología, 1983
The biliary secretion in response to food has been studied in chicken. In this species, a well de... more The biliary secretion in response to food has been studied in chicken. In this species, a well defined biliary postprandial response with a clear vesicular component can be estimated. The bile salt independent fraction increases after feeding. Our results show that gallbladder bile has a lower osmotic power. The biliary response to food when the enterohepatic circulation is blocked, diminishes. The relationship between bile salt independent fraction values, whether the vesicular duct is tied or not, remains constant when the enterohepatic circulation is interrupted.
Physiologia Bohemoslovaca, 1985
Basal exocrine pancreatic secretion was studied in anaesthetized and conscious chickens and spont... more Basal exocrine pancreatic secretion was studied in anaesthetized and conscious chickens and spontaneous secretion was studied in anaesthetized chickens. Results are compared with those of other vertebrates to estimate the specific pattern of this secretion in birds. The flow of pancreatic juice was greater in conscious chickens than when anaesthetized (Table 1). Amylase activity was greater than that of the other species and was of the same order in anaesthetized and conscious birds (Table 1). A spontaneous exocrine pancreatic secretion was seen to remain after eliminating a large part of the tonic influences (Table 2).
Comparative Biochemistry and Physiology Part A: Physiology, 1981
... Dl;roNi J. .1. HHN & S(RAT(HI,RI> T. (1974) Further evi-dence that secretin stimulates... more ... Dl;roNi J. .1. HHN & S(RAT(HI,RI> T. (1974) Further evi-dence that secretin stimulates pancreatic secretion through adenosine 3'-5'-monophosphatc (c-AMP). ,/. ... 200,478. WAELE B.. DESMUL A.. WISSOCQ P. & LIEKENS R. (1974) La secretion pancr atique chez le rat. ...
Quarterly Journal of Experimental Physiology, 1981
The biliary response to feeding has been investigated in intact and cholecystectomized rabbits, w... more The biliary response to feeding has been investigated in intact and cholecystectomized rabbits, with and without interruption of the enterohepatic circulation of bile salts. The relative contribution of the different secretory mechanisms involved in this process has been examined. Feeding induced an increase in the flow and bicarbonate concentration of the bile and a slight decrease in the bile salt content in rabbits with gall bladders and the enterohepatic circulation intact. Feeding with the enterohepatic circulation interrupted elicited a drop in bile flow and the bile salt concentration, but an increase in bicarbonate concentration. Interruption of the enterohepatic circulation thus dramatically modifies the feeding response: a response to food is still detectable after interruption, but is masked by the negative effects of drainage of the bile away from the duodenum.
Quarterly Journal of Experimental Physiology, 1981
The role of enterohepatic circulation of bile salts in biliary secretion in conscious rabbits has... more The role of enterohepatic circulation of bile salts in biliary secretion in conscious rabbits has been investigated before and after cholecystectomy. Bile flow was higher and bile salt concentration lower in cholecystectomized than in intact rabbits: this could have been caused by a negative feedback effect on bile salt synthesis as the circulating bile salt pool increased. The effects of cholecystectomy on flow and bile salt concentration balanced each other. Bile flow and bile salt concentration declined after interruption of the enterohepatic circulation in both cholecystectomized and intact rabbits. Furthermore, the percentage of the flow of bile independent of bile salt secretion increased, while that independent of total analysed solutes decreased after the enterohepatic circulation was broken. These results confirm that the decrease in bile flow after interruption of the enterohepatic circulation is due to loss of bile salts and not of electrolytes. * See Methods.
The Open Gastroenterology Journal, 2011
European Journal of Pharmacology, 2007
We examined the ability of the flavonoids quercetin and kaempferol to modulate inducible nitric o... more We examined the ability of the flavonoids quercetin and kaempferol to modulate inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and reactive C-protein (CRP) expression, and to induce changes in the nuclear factor kappa B (NF-κB) pathway in the human hepatocyte-derived cell line Chang Liver. Cells were incubated with a cytokine mixture supplemented with quercetin or kaempferol (5 to 200 μmol/l). Kaempferol produced a significant concentration-dependent decrease of iNOS, COX-2 and CRP protein level at all concentrations, but the percentage of inhibition induced by quercetin was reduced at high concentrations. Both flavonoids significantly inhibited mRNA level of iNOS, COX-2, and CRP. Inhibitory effects by quercetin and kaempferol were also observed on NF-κB activation and on protein concentration of the phosphorylated form of the inhibitor IκBα and of IKK (IκB kinase)α. The present study suggests that the modulation of iNOS, COX-2 and CRP by quercetin or kaempferol may contribute to the anti-inflammatory effects of these two structurally similar flavonoids in Chang Liver cells, via mechanisms likely to involve blockade of NF-κB activation and the resultant up-regulation of the pro-inflammatory genes. Our data also indicate that the minor structural differences between both compounds determine differences in their inhibitory capacity.
Publisher Summary This chapter describes the effect of bile salts on the excretion of bilirubin b... more Publisher Summary This chapter describes the effect of bile salts on the excretion of bilirubin by the rabbit. It describes an experiment in which animals were anaesthetized with pentobarbital sodium intravenously. A catheter was placed in the left femoral vein for administration of fluids. The cystic duct was ligated and a catheter was placed in the common duct. Rectal temperature was maintained at 38.5°C ± 0.5°C on a heating table. After an equilibrium period of 30 min, an infusion of bilirubin was initiated at a rate of 0.6 mg/kg body wt/min (period A). This rate was chosen because higher rates do not result in an increase of maximal excretion whose value was 0.94 μEq/kg body wt/min similar to those previously reported in the rat, sheep, and rhesus monkey. An hour later, a simultaneous bile salt infusion was given for 60 min at a rate of 0.9 mg/kg body wt/min (period B). Two micelle forming salts, namely, glycodeoxycholate and taurocholate, and one synthetic salt not forming micelles in vitro , that is, dehydrocholate, were tested. It was found that the three bile salts have a similar effect on the maximal excretion of bilirubin.
British Journal of Experimental Pathology, Dec 1, 1987
Biliary calcium secretion during liver regeneration following two-thirds hepatectomy was studied ... more Biliary calcium secretion during liver regeneration following two-thirds hepatectomy was studied in Wistar rats. Calcium output per Ioo g body weight was significantly reduced at 24 h post-hepatectomy but not at other times. Values per gram of liver were significantly increased at 48 h and 96 h. A significant relationship was found between bile acid output and calcium output into bile both in controls and hepatectomized animals. The number of nmol of calcium secreted per nmol of bile acids was increased at 24 h post-hepatectomy parallel to an increased choleretic capacity of bile acids and a decrease in the fraction of bile acid independent flow. Our data confirm that bile acid secretion is an important determinant in the secretion of calcium into bile after partial hepatectomy in the rat.