Gerber D, Davies M, Hokin L E
J Cell Biol. 1973 Mar;56(3):736-45. doi: 10.1083/jcb.56.3.736.
Stimulation of enzyme secretion in the pancreas on injection of a single dose of the cholinergic drug, pilocarpine, was associated with an increased incorporation of [2-(3)H]myoinositol into a lipid, which was previously characterized as phosphatidylinositol. Stimulation of enzyme secretion by hourly injection of the pancreozymin congener, caerulein, led to more increased phosphatidylinositol synthesis than with a single injection of pilocarpine. The amylase level of the pancreas remained at a low level as long as caerulein was injected, indicating continued stimulation of enzyme secretion even though increased phosphatidylinositol synthesis ceased after 6 h. Feeding gave the same stimulation of phosphatidylinositol synthesis as caerulein. The major synthesis of phosphatidylinositol in controls and the stimulation of phosphatidylinositol synthesis by pilocarpine was entirely confined to the microsome fraction throughout the experiments (up to 18 h). This shows that there is no flow of microsomal membrane (smooth- or rough-surfaced endoplasmic reticulum) to other membranous structures throughout the secretory cycle and beyond. It is concluded that the stimulation of phosphatidylinositol synthesis by pancreatic secretagogues is confined to microsomal elements and does not play any role in membrane flow.
注射单剂量胆碱能药物毛果芸香碱刺激胰腺酶分泌时，伴随着[2-(3)H]肌醇掺入一种脂质的增加，该脂质先前被鉴定为磷脂酰肌醇。每小时注射促胰液素同类物蛙皮素刺激酶分泌，导致磷脂酰肌醇合成的增加比单次注射毛果芸香碱更多。只要注射蛙皮素，胰腺淀粉酶水平就保持在低水平，这表明即使磷脂酰肌醇合成在6小时后停止，酶分泌仍持续受到刺激。喂食对磷脂酰肌醇合成的刺激与蛙皮素相同。在整个实验过程（长达18小时）中，对照组中磷脂酰肌醇的主要合成以及毛果芸香碱对磷脂酰肌醇合成的刺激完全局限于微粒体部分。这表明在整个分泌周期及之后，微粒体膜（光滑或粗糙表面的内质网）不会流向其他膜结构。得出的结论是，胰腺促分泌剂对磷脂酰肌醇合成的刺激局限于微粒体成分，在膜流动中不起任何作用。
