Diurnal variations in insulin secretion and K+ permeability in isolated rat islets
Diurnal variations in insulin secretion and K+ permeability in isolated rat islets
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DOI：
10.1046/j.1440-1681.1999.03073.x
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发表时间：
1999-07-01
影响因子：
2.9
通讯作者：
Boschero, AC
中科院分区：
文献类型：
--
作者：
Delattre, E;Cipolla-Neto, J;Boschero, AC
1.在24 h内的6个时间点（00. 00、04. 00、08. 00、12. 00、16. 00和20. 00 h）观察葡萄糖对大鼠胰岛分泌胰岛素和Rb-86外排的影响。在不存在葡萄糖和存在亚刺激浓度（2.8 mmol/L）的糖的情况下，胰岛素分泌不随一天中的时间而变化。葡萄糖浓度为5.6 mmol/L时，刺激胰岛素分泌仅在20.00 h时高于基础水平，3.在较高的糖浓度（8.3mmol/L）下，胰岛素分泌的增加和Rb-86外排率的降低在黑暗期更为显著。当葡萄糖浓度高于8.3 mmol/L（27.7 mmol/L除外）时，胰岛素分泌不受时间的影响。一天中的时间似乎主要在葡萄糖浓度接近生理值（5.6-8.3 mmol/L）时影响胰岛素分泌。该结果与生理量的葡萄糖在相同时间间隔改变胰腺B细胞Rb-86渗透性的能力一致。
1. The effects of glucose on insulin secretion and Rb-86 efflux from isolated rat islets were studied at six different times during a 24-h period (00.00, 04.00, 08.00, 12.00, 16.00 and 20.00 h),2. In the absence of glucose and in the presence of substimulatory concentrations (2.8 mmol/L) of the sugar, insulin secretion did not vary with the time of day. At a glucose concentration of 5.6 mmol/L the stimulated insulin secretion was greater than basal levels only at 20.00 h,3. At a higher sugar concentration (8.3 mmol/L) the increase in insulin secretion and the reduction in Rb-86 efflux rate were more marked during the dark period. No effect of the time of day on insulin secretion was observed at glucose concentrations above 8.3 mmol/L (except in 27.7 mmol/L),4. The time of day appears to affect insulin secretion mainly at glucose concentrations close to physiological values (5.6-8.3 mmol/L),5. This result agrees with the ability of physiological amounts of glucose to alter the Rb-86-permeability of pancreatic B cells at the same time intervals.