Unaltered oxygen tension in rat pancreatic islets despite dissociation of insulin release and islet blood flow
Unaltered oxygen tension in rat pancreatic islets despite dissociation of insulin release and islet blood flow
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DOI：
10.1046/j.1365-201x.2002.01049.x
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发表时间：
2002-12-01
期刊：
影响因子：
--
通讯作者：
Palm, F
中科院分区：
文献类型：
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作者：
Carlsson, PO;Jansson, L;Palm, F
本研究调查了在不同的胰岛素释放需求期间，严格调节胰岛血流对于优化胰岛组织氧合的重要性。将葡萄糖和/或非特异性一氧化氮合酶抑制剂(L-NNA)静脉注入未处理或去迷走神经的大鼠，测量胰岛血流量、血氧分压和血清胰岛素浓度。用非放射性微球技术测量胰岛血流量，用Clark微电极记录组织氧分压，用酶联免疫吸附测定技术测定胰岛素浓度。给予L-NNA(0.3 mg·kg~(-1)·min~(-1))10min可使基础胰岛血流量减半，但不影响血清胰岛素浓度。给予葡萄糖(10 mg·kg~(-1))1min(~(-1))可引起胰岛血流量显著增加，此作用可被迷走神经切断术或L-NNA阻断。所有注射葡萄糖的动物的血清胰岛素浓度均升高。尽管采取了这些干预措施，所有动物的胰岛组织氧分压仍保持相似。胰岛组织的氧合以外的原因必须解释通常存在的胰岛血流的严格调节。
The present study investigated the importance of a tightly regulated islet blood flow for an optimal oxygenation of the islet tissue during different demands for insulin release. Glucose and/or a nonspecific nitric oxide synthase inhibitor (L-NNA) were infused intravenously in non-pretreated or vagotomized rats and the animals were subjected to measurements of islet blood flow, oxygen tension and serum insulin concentrations. Islet blood flow was measured using a non-radioactive microsphere technique, tissue oxygen tension was recorded with Clark microelectrodes and insulin concentrations were determined by enzyme-linked immunosorbent assay technique. Administration of L-NNA (0.3 mg kg(-1) min(-1)) for 10 min halved basal islet blood flow, but did not affect serum insulin concentrations. Glucose administration (10 mg kg) 1 min(-1)) induced a marked increase in islet blood flow, which could be prevented by vagotomy or L-NNA. The serum insulin concentrations increased in all glucose-infused animals. The islet tissue oxygen tension remained similar in all animals despite these interventions. Reasons other than oxygenation of the islet tissue must explain the normally existing tight regulation of islet blood flow.