Nicotinic cholinergic influences in pancreatic secretion induced by intraduodenal alkaline and acid solutions in the rabbit.
1. The effect of hexamethonium on the exocrine pancreatic response to intraduodenal acidification and alkalinization, and the secretin and VIP release after these stimuli, was studied. 2. The hydroelectrolyte secretion after hydrochloric acid and sodium carbonate perfusion was reduced by hexamethonium treated (322 +/- 44% of maximum response in flow rate to sodium carbonate perfusion in untreated animals vs 140 +/- 12% in pretreated animals, and 252 +/- 19% of maximum response in flow rate to HCl in untreated animals vs 166 +/- 11% in pretreated animals). 3. However, hexamethonium has no effect on secretin plasma levels after either intraduodenal acidification or alkalinization. 4. On the contrary, the ganglion blocker significantly (P < 0.01) reduced plasma VIP levels in response to intraduodenal HCl (maximum response 320 +/- 74% in untreated vs 184 +/- 44% in hexamethonium-treated animals). 5. Plasma VIP levels showed a similar increase in both untreated (maximum response: 151 +/- 12%) and ganglion blocked animals (170 +/- 26%) in response to sodium carbonate. 6. These data suggest the existence of complex neural mechanisms in the exocrine pancreatic response to intraduodenal stimuli, these mechanisms being different depending on the intraduodenal stimulus.
Bragado
M J
MJ
Departamento de Fisiología y Farmacología, Universidad de Salamanca, Spain.
García
L J
LJ
Montero
A
A
San Román
J I
JI
Calvo
J J
JJ
López
M A
MA
D000143:Acids / Q000008:administration & dosage / Q000494:pharmacology*; D000468:Alkalies / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002254:Carbonates / Q000494:pharmacology; D004386:Duodenum; D006584:Hexamethonium Compounds / Q000494:pharmacology; D006851:Hydrochloric Acid / Q000494:pharmacology; D007441:Intubation, Gastrointestinal; D008297:Male; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D010189:Pancreatic Juice / Q000187:drug effects / Q000378:metabolism; D010275:Parasympathetic Nervous System / Q000187:drug effects*; D011817:Rabbits; D011978:Receptors, Nicotinic / Q000187:drug effects*; D012633:Secretin / Q000378:metabolism; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism
D000143:Acids; D000468:Alkalies; D002254:Carbonates; D006584:Hexamethonium Compounds; D011978:Receptors, Nicotinic; D012633:Secretin; D014660:Vasoactive Intestinal Peptide; C005686:sodium carbonate; D006851:Hydrochloric Acid