Hallberg A, Andersson A
Diabetes Res. 1984 Jul;1(2):105-10.
It was the aim of the present study to examine the extent to which starvation-induced impairment of glucose-stimulated insulin secretion is linked to changes of islet phospholipid metabolism. For this purpose both islets isolated from mice starved for 60 hr and islets maintained in culture for 1 week in a low (3.3 mM) glucose medium were studied together with relevant control islets. When challenged with a high glucose concentration the insulin response of both groups of islets was totally blunted. The effect of food restriction on 14C-glucose incorporation into different phospholipid classes was less prominent. On a percentage basis phosphatidylserine biosynthesis of islets isolated from starved mice was most affected, whereas the biosynthesis of phosphatidylcholine was only marginally impaired. Culture of islets for 1 week at the low glucose concentration affected the phospholipid biosynthesis even less and there was only a small decrease of 14C-glucose incorporation into phosphatidylcholine. In general, cultured islets synthesized more phospholipids than the freshly isolated ones. No dose-response relationship was found between various degrees of glucose-stimulated insulin secretion and 14C-glucose incorporation into different phospholipid classes of islets isolated from fed mice. The present data thus provided no evidence that an impairment of the islet phospholipid turnover contributes to the starvation-induced impairment of insulin secretion. There was also no close correlation between phospholipid biosynthesis in terms of 14C-glucose incorporation and glucose-stimulated insulin secretion.
本研究的目的是探讨饥饿诱导的葡萄糖刺激的胰岛素分泌受损与胰岛磷脂代谢变化之间的关联程度。为此，对从饥饿60小时的小鼠分离的胰岛以及在低（3.3 mM）葡萄糖培养基中培养1周的胰岛与相关对照胰岛进行了研究。当用高葡萄糖浓度刺激时，两组胰岛的胰岛素反应均完全减弱。食物限制对14C-葡萄糖掺入不同磷脂类别的影响不太显著。从百分比来看，从饥饿小鼠分离的胰岛中磷脂酰丝氨酸的生物合成受影响最大，而磷脂酰胆碱的生物合成仅略有受损。在低葡萄糖浓度下将胰岛培养1周对磷脂生物合成的影响更小，14C-葡萄糖掺入磷脂酰胆碱仅略有减少。一般来说，培养的胰岛比新鲜分离的胰岛合成更多的磷脂。在喂食小鼠分离的胰岛中，不同程度的葡萄糖刺激的胰岛素分泌与14C-葡萄糖掺入不同磷脂类别之间未发现剂量反应关系。因此，目前的数据没有提供证据表明胰岛磷脂周转受损导致饥饿诱导的胰岛素分泌受损。就14C-葡萄糖掺入而言，磷脂生物合成与葡萄糖刺激的胰岛素分泌之间也没有密切相关性。
