MacAdams M R, Pek S B, Lands W E
Endocrinology. 1984 Apr;114(4):1364-70. doi: 10.1210/endo-114-4-1364.
The influence of different levels of inhibition of prostaglandin (PG) synthesis on the release of insulin and glucagon was investigated in the basal state (5.6 mM glucose) and in response to 30-min perfusion of 16.7 mM glucose using the isolated perfused rat pancreas model. Flurbiprofen (FLR), a potent and selective inhibitor of PG synthesis, was present in the perfusate during the entire experimental period at a concentration of 10(-8), 5 X 10(-8), or 10(-6) M; control experiments were performed without the drug. Levels of immunoreactive PGE2, PGF2 alpha, insulin, and glucagon were measured in the portal venous effluent. FLR inhibited PG synthesis in a dose-related manner; PGE2 was inhibited more than PGF2 alpha. Basal and glucose-induced secretion of insulin was augmented by FLR at 5 X 10(-8) M, but was inhibited at 10(-6) M. At 10(-6) M FLR, basal glucagon secretion was inhibited; glucose-induced suppression still occurred without any potentiation. We conclude that 1) endogenous PGs modulate the secretion of insulin and glucagon; 2) divergence of the effects of low and high levels of inhibition of PG biosynthesis on insulin release may be due to altered tissue proportions of various PGs and related autacoids; and 3) the predominant effect of endogenous PGs on glucagon release is tonic stimulation.
利用离体灌注大鼠胰腺模型,研究了在基础状态(5.6 mM葡萄糖)以及对16.7 mM葡萄糖进行30分钟灌注时,不同水平抑制前列腺素(PG)合成对胰岛素和胰高血糖素释放的影响。氟比洛芬(FLR)是一种强效且选择性的PG合成抑制剂,在整个实验期间,其在灌注液中的浓度为10(-8)、5×10(-8)或10(-6) M;进行了无药物的对照实验。在门静脉流出液中测量免疫反应性PGE2、PGF2α、胰岛素和胰高血糖素的水平。FLR以剂量相关的方式抑制PG合成;PGE2比PGF2α受到的抑制更明显。5×10(-8) M的FLR增强了基础状态和葡萄糖诱导的胰岛素分泌,但在10(-6) M时则受到抑制。在10(-6) M的FLR作用下,基础胰高血糖素分泌受到抑制;葡萄糖诱导的抑制作用仍然存在,且没有任何增强作用。我们得出以下结论:1)内源性PG调节胰岛素和胰高血糖素的分泌;2)低水平和高水平抑制PG生物合成对胰岛素释放的影响存在差异,可能是由于各种PG和相关自分泌物质的组织比例发生了改变;3)内源性PG对胰高血糖素释放的主要作用是持续性刺激。