PUTATIVE MEDIATORS OF INSULIN SECRETION

胰岛素分泌的假定介质包括钙、胰高血糖素和胰高血糖素。 环核苷酸 我研究的重点是确定合成的 后两种介质在来自大鼠胰腺的分离胰岛中的概况，以及 以确定它们在胰岛素分泌过程中的参与。 使用 分离的胰岛匀浆，我们不仅研究合成的 主要的木兰素，还有它们的新陈代谢。 生物化学途径， 包括花生四烯酸通过前列腺素的代谢 环氧合酶、15-酮脱氢酶和还原酶。 小说的证据 也正在研究胰岛组织中的脂氧合酶途径。 此外我们 正在比较外分泌组织（腺泡） 具有胰岛中发现的特征的造血细胞。 合成前列腺素 也将在完整的胰岛中进行研究，以及在分离的细胞中， 破坏的小岛 将使用各种胰岛素促泌剂来研究 刺激时胰岛前列腺素合成和代谢的反应 分泌和/或合成。 关于前列腺素的合成，磷脂酶A2（PLA 2）的活性 被认为决定了细胞对花生四烯酸的利用率 前列腺素合成 在分离的胰岛造血细胞中，PLA 2的活性是 正在评估，胰岛素促分泌素对酶活性的影响， 被确定。 我之前的研究表明环鸟苷-3 '，5'-单磷酸 (GMP)可能在胰岛素的第一阶段释放中起作用。 更清楚 了解胰岛素释放对环GMP水平的依赖性 分离的胰岛是要寻找的，鉴于环核苷酸调节 钙交换现象和可能的其他细胞生物化学活动。 一 鸟苷酸环化酶与磷脂酶A_2活性的关系 完整的细胞一直是一个难以捉摸的问题，也许细胞水平的花生四烯酸 酸或洋地黄素是重要因素。

Putative mediators of insulin secretion include calcium, prostaglandins, and cyclic nucleotides. The focus of my reseach is to determine the synthetic profiles of the latter two mediators in isolated islets from rat pancreas, and to determine their participation in the process in insulin secretion. Using homogenates of isolated islets, we are studing not only the synthesis of the primary prostaglandins, but also their metabolism. The biochemical pathways we are investigating include arachidonate metabolism through prostaglandin cyclooxygenase, 15-keto-dehydrogease, and reductase. Evidence for a novel liproxygenase pathways in islet tissue is also being studied. In addition we are comparing the prostaglandin synthesis profile of exocrine tissue (acinar) hemogenates with the profile found in islets. The synthesis of prostaglandins will also be studied in intact islet, as well as in isolated cells from disrupted islets. Various insulin secretogogues will be used to study the response of prostaglandin synthesis and metabolism in islets during stimulation of secretion and/or synthesis. With regard to prostaglandin synthesis, the activity of phospholipase A2 (PLA2) is believed to determine the availability of arachidonic acid for cell prostaglandin synthesis. The activity of PLA2 in insolated islet hemogenates is being assessed, and the effect of insulin secretogogues on enzyme activity is being determined. My previous research has suggested that cyclic guanosine-3',5'-monophosphate (GMP) may play a role in the first-phase release of inslin. A more clear understanding of the dependence of insulin release on cyclic GMP levels in the isolated islet is to be sought, with the view that cyclic nucleotides regulate calcium exchange phenomena and perhaps other cellular biochemical activities. A relationship between the activity of PLA2 and guanylate cyclase activity in intact cells has been an elusive problem, and perhaps cell levels of arachidonic acid or prostaglandins are important factors.