Homma T, Malik K U
Am J Physiol. 1983 Jun;244(6):G660-7. doi: 10.1152/ajpgi.1983.244.6.G660.
We investigated the effect of secretin and caerulein on pancreatic circulation and exocrine secretion and its relation to prostaglandin (PG) synthesis by studying the effect of these peptides on the pancreatic blood flow and the flow rate of pancreatic exocrine secretion in the isolated blood-perfused pancreas of pentobarbital-anesthetized dogs without or with pretreatment with the cyclooxygenase inhibitors, indomethacin and meclofenamate. Intra-arterial administration of secretin (0.1-0.3 U/kg) produced an initial vasoconstriction followed by vasodilation. On the other hand, caerulein (50-200 ng/kg) produced vasodilation and increased pancreatic blood flow in a dose-related manner. Both secretin and caerulein increased the flow rate of pancreatic exocrine secretion. In animals pretreated with either indomethacin or meclofenamate, the ability of secretin to produce an initial vasoconstriction was abolished and the subsequent vasodilator component of the response as well as caerulein-induced vasodilation were reduced in duration. The effect of caerulein but not of secretin to stimulate the flow rate of pancreatic exocrine secretion was reduced by indomethacin and meclofenamate. Administration of PGI2 and PGE2 into the pancreas caused vasodilation, whereas PGF2 alpha and PGD2 produced a biphasic effect, i.e., an initial vasoconstriction followed by vasodilation. Infusion of either PGI2 or PGE2 but not that of PGF2 alpha or PGD2 minimized the effect of cyclooxygenase inhibitors to reduce the duration of vasodilator response elicited by secretin and caerulein. Prostaglandins neither altered the basal nor the rise in flow rate of pancreatic exocrine secretion produced by secretin and caerulein. These data indicate that in the canine pancreas prostaglandins contribute to the effects of secretin and caerulein to increase pancreatic blood flow but not to their effect on pancreatic exocrine secretion.
我们通过研究这些肽对戊巴比妥麻醉犬的离体血液灌注胰腺的胰腺血流和胰腺外分泌分泌流速的影响，探讨了促胰液素和蛙皮素对胰腺循环和外分泌分泌的作用及其与前列腺素（PG）合成的关系，实验中使用或未使用环氧化酶抑制剂吲哚美辛和甲氯芬那酸进行预处理。动脉内注射促胰液素（0.1 - 0.3 U/kg）会先引起血管收缩，随后血管舒张。另一方面，蛙皮素（50 - 200 ng/kg）会引起血管舒张，并以剂量相关的方式增加胰腺血流。促胰液素和蛙皮素均增加了胰腺外分泌分泌的流速。在用吲哚美辛或甲氯芬那酸预处理的动物中，促胰液素产生初始血管收缩的能力被消除，随后反应的血管舒张成分以及蛙皮素诱导的血管舒张的持续时间缩短。吲哚美辛和甲氯芬那酸降低了蛙皮素而非促胰液素刺激胰腺外分泌分泌流速的作用。向胰腺内注射前列环素（PGI2）和前列腺素E2（PGE2）会引起血管舒张，而前列腺素F2α（PGF2α）和前列腺素D2（PGD2）产生双相作用，即先血管收缩后血管舒张。输注PGI2或PGE2而非PGF2α或PGD2可使环氧化酶抑制剂减少促胰液素和蛙皮素引起的血管舒张反应持续时间的作用最小化。前列腺素既不改变促胰液素和蛙皮素引起的胰腺外分泌分泌流速的基础值，也不改变其升高值。这些数据表明，在犬胰腺中，前列腺素有助于促胰液素和蛙皮素增加胰腺血流的作用，但对它们对胰腺外分泌分泌的作用没有贡献。
