GLUCOSE-INDUCED CHANGES IN PANCREATIC-ISLET BLOOD-FLOW MEDIATED BY CENTRAL-NERVOUS-SYSTEM
GLUCOSE-INDUCED CHANGES IN PANCREATIC-ISLET BLOOD-FLOW MEDIATED BY CENTRAL-NERVOUS-SYSTEM
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DOI：
10.1152/ajpendo.1986.251.6.e644
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发表时间：
1986-12-01
影响因子：
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通讯作者：
HELLERSTROM, C
中科院分区：
文献类型：
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作者：
JANSSON, L;HELLERSTROM, C
早期使用微球技术的实验表明，血糖浓度升高会持续导致胰岛血流量(IBF)的增加。一些证据表明，这种对葡萄糖敏感的控制机制位于胰腺外部位。这项研究的目的是确定中枢神经系统在这种机制中可能发挥的作用。因此，D-葡萄糖、L-葡萄糖、3-O-甲基葡萄糖或生理盐水被注入颈动脉，每个剂量为1毫克。体重wt-1.cntdo.Min-1灌胃3min，测定胰腺和胰岛血流量。所有这些物质都不影响全身血糖水平。然而，颈动脉内注射D-葡萄糖引起血清胰岛素浓度和IBF的迅速增加。然而，流向整个胰腺的血流量保持不变，表明腺体内的血流量重新分配。颈动脉注入其他试验物质或在股静脉中给予类似数量的D-葡萄糖并不影响这些参数。切断迷走神经或应用阿托品均可消除D-葡萄糖引起的血清胰岛素浓度升高和IBF升高。当通过腹腔注射葡萄糖(2g/kg体重)增加全身血糖浓度时，切断迷走神经阻断了胰岛血流量的增加，但不能阻止伴随的胰岛素释放。这些观察结果表明，葡萄糖诱导的IBF增加是由迷走神经胆碱能影响介导的。这种迄今未被描述的机制可能代表一条反射弧线，与可能的局部因素一起，确保在代谢需求增加的时期向胰岛器官提供足够的血液供应。它还可以提供一种在用餐后立即将胰岛素快速散布到肝脏的方法。
Earlier experiments with the microsphere technique suggested that a heightened serum glucose concentration consistently leads to an increase in islet blood flow (IBF). Several lines of evidence suggest that this glucose-sensitive control mechanism is located at an extrapancreatic site. The purpose of this study was to define the possible role of the central nervous system in such a mechanism. D-glucose, L-glucose, 3-O-methylglucose, or saline were therefore infused into the carotid artery, each at a dose of 1 mg .cntdot. kg body wt-1 .cntdot. min-1 for 3 min, and the pancreatic and islet blood flows were measured. None of these substances affected the systemic serum glucose level. The intracarotid infusion of D-glucose, however, caused a rapid increase in both the serum insulin concentration and IBF. The blood flow to the whole pancreas nevertheless remained unchanged, indicating a redistribution of flow within the gland. Carotid infusion of the other test substances or a similar amount of D-glucose given in a femoral vein did not affect these parameters. Both the increase in serum insulin concentration and the increase in IBF caused by D-glucose could be abolished by vagotomy or administration of atropine. When the systemic blood glucose concentration was increased by intraperitoneal glucose administration (2 g/kg body wt), vagotomy blocked the increase in islet blood flow but not the concomitant insulin release. These observations suggest that the glucose-induced increase in IBF is mediated by vagal cholinergic influences. This hitherto undescribed mechanism may represent a reflex arc, which, together with possible local factors, ensures an adequate blood supply to the islet organ during periods of increased metabolic demands. It may also provide a means of rapid dispersal of insulin to the liver immediately after a meal.