REGULATION OF PHOSPHOLIPID HYDROLYSIS IN STREPTOLYSIN-O-PERMEABILIZED RAT PANCREATIC ACINI

被引：5

作者：

MATOZAKI, T ^{[1
]}

WILLIAMS, JA ^{[1
]}

机构：

[1] UNIV MICHIGAN,DEPT PHYSIOL,7744 MED SCI 2,ANN ARBOR,MI 48109

来源：

PANCREAS | 1992年 / 7卷 / 01期

关键词：

CHOLECYSTOKININ; PERMEABILIZED PANCREATIC ACINI; PHOSPHOLIPID HYDROLYSIS; G-PROTEIN; CALCIUM;

D O I：

10.1097/00006676-199201000-00010

中图分类号：

R57 [消化系及腹部疾病];

学科分类号：

摘要：

To investigate the mechanism of phospholipid hydrolysis in pancreatic acinar cells, the effects of Ca2+, guanosine 5'-O-(3-thiotriphosphate) (GTP-gamma-S) and cholecystokinin (CCK) on both polyphosphoinositide (PI) and phosphatidylcholine (PC) hydrolysis were studied in rat pancreatic acini permeabilized with the bacterial toxin, streptolysin-O. When acini were prelabeled with myo-[H-3]inositol, permeabilized, and then incubated with various concentrations of free Ca2+ for 15 min, Ca2+ stimulated [H-3]inositol phosphate release at a concentration of 100 nM and was maximally effective at 100-mu-M. Both GTP-gamma-S and CCK enhanced Ca2+-induced [H-3]inositol phosphate release, although these agents had no effect in the absence of Ca2+. At a physiological concentration of Ca2+ (100 nM), CCK stimulated [H-3]inositol phosphate release which was further enhanced by GTP-gamma-S. When acini were similarly prelabeled with [H-3]choline before permeabilization, [H-3]choline phosphate release was also stimulated by free Ca2+ over the concentration range from 100 nM to 10-mu-M. In contrast to PI hydrolysis, however, neither GTP-gamma-S, CCK, or GTP-gamma-S plus CCK had an additional effect on [H-3]choline phosphate release stimulated by 100 nM-100-mu-M free Ca2+. Furthermore, Ca2+-induced [H-3]choline phosphate release appeared to be due to the redistribution from cell to the medium rather than to an increase in choline phosphate production. Therefore, choline phosphate release following prelabeling with [H-3]choline is not useful as an indicator of PC hydrolysis in permeabilized acini.

引用

页码：59 / 65

页数：7

共 36 条

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