DIACYLGLYCEROL SYNTHESIS DENOVO FROM GLUCOSE BY PANCREATIC-ISLETS ISOLATED FROM RATS AND HUMANS

被引:77
作者
WOLF, BA
EASOM, RA
MCDANIEL, ML
TURK, J
机构
[1] WASHINGTON UNIV,SCH MED,DEPT INTERNAL MED,DIV LAB MED,BOX 8118,660 S EUCLID AVE,ST LOUIS,MO 63110
[2] WASHINGTON UNIV,SCH MED,DEPT PATHOL,DIV LAB MED,ST LOUIS,MO 63110
关键词
diacylglycerol; insulin; pancreatic islets;
D O I
10.1172/JCI114463
中图分类号
R-3 [医学研究方法]; R3 [基础医学];
学科分类号
1001 ;
摘要
Recent evidence has suggested that pancreatic islets isolated from rats synthesize 1,2-diacyl-sn-glycerol (DAG) de novo from glucose and that this process may constitute the long-sought link between the metabolism of glucose and the induction of insulin secretion. The cell-permeant diacylglycerol 1-oleoyl-2-acetyl-sn-glycerol (200 μM) has been found here to amplify both the first and second phases of insulin secretion from perifused human islets. Measurements of the mass of endogenous DAG in human pancreawstic islets by enzymatic and by mass spectrometric methods indicate that levels of 200 μM may be achieved under physiologic conditions. Conversion of [14]Cglucose to [14C]DAG has been demonstrated here to occur within 60 s of exposure of rat and human islets to stimulatory concentrations of glucose. This process has been found to be a quantitatively minor contributor to the total islet DAG mass after acute stimulation with glucose, however, and glucose has been found not to induce a rise in total islet DAG content within 20 min of induction of insulin secretion. In contrast to the case with rodent islets, two pharmacologic inhibitors of DAG-induced activation of protein kinase C (staurosporine and sphingosine) have been found not to influence glucose-induced insulin secretion from isolated human islets. These findings indicate that de novo synthesis of DAG from glucose does not participate in acute signal-response coupling in islets.
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页码:482 / 490
页数:9
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