The effects of arginine vasopressin (AVP) on pancreatic ductal secretion were studied in guinea pigs. In the isolated vascularly perfused pancreas, AVP reduced secretin-stimulated fluid secretion and increased the vascular resistance when the perfusion rate was held constant. In the isolated interlobular duct segments, AVP inhibited secretin-stimulated fluid secretion, indicating the direct inhibitory action of AVP on the duct cells. AVP affected neither the basal nor the secretin-induced cAMP productions, suggesting that AVP inhibits the fluid secretion at a point distal to the production of cAMP. AVP increased intracellular Ca2+ concentration ([Ca2+](i)) in the absence of extracellular Ca2+. When [Ca2+](i) was elevated by the application of thapsigargin, AVP caused a rapid decrease in [Ca2+](i). AVP seems to activate both Ca2+ release from intracellular stores and Ca2+ efflux across the plasma membrane, but its relation to the inhibition of fluid secretion remains to be clarified. It is concluded that AVP directly inhibits secretin-stimulated ductal fluid secretion in the guinea pig pancreas.
|ジャーナル||American Journal of Physiology - Gastrointestinal and Liver Physiology|
|出版ステータス||Published - 1999 7月|
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