Jun T, Sakinis A, Wennmalm A
Division of Clinical Physiology, Göteborg University, Sweden.
Acta Physiol Scand. 1995 Sep;155(1):61-5. doi: 10.1111/j.1748-1716.1995.tb09948.x.
In isolated pancreative beta cells from rats the insulin secretory response to glucose is amplified by L-arginine. Since this effect is inhibited by NO synthesis inhibitors, and since L-arginine is precursor of NO, the observation indicates a role for NO in insulin secretion from beta cells. We recently reported that i.v. L-arginine elicited insulin secretion in anaesthetized rats by a mechanism that was partly NO dependent. The aim of the present study was to assess if the insulin secretory response to an intravenous infusion of glucose also requires an intact NO formation. Anaesthetized rats were given D-glucose (100 mg kg-1 min-1 i.v. for 30 min). Plasma insulin (PI), blood glucose (BG) levels and mean arterial blood pressure (MAP) were assessed from before and until 15 min after the end of the infusion. One group of rats were untreated and served as controls. The two other groups were pretreated with either of the NO synthase inhibitors NW-nitro-L-arginine methyl ester (L-NAME, 50 mg kg-1 i.v.), or NG-monomethyl-L-arginine (L-NMMA, 100 mg kg-1 i.v.). In controls infusion of glucose elevated PI by up to 25 +/- 3 U L-1, and BG by up to 27 +/- 1 mmol L-1. Pretreatment with L-NAME elevated MAP from 74 +/- 6 to 132 +/- 4 mmHg, indicating that NO synthase was inhibited.(ABSTRACT TRUNCATED AT 250 WORDS)
在分离的大鼠胰腺β细胞中，L-精氨酸可增强对葡萄糖的胰岛素分泌反应。由于这种效应被一氧化氮（NO）合成抑制剂所抑制，且L-精氨酸是NO的前体，该观察结果表明NO在β细胞胰岛素分泌中发挥作用。我们最近报道，静脉注射L-精氨酸可通过部分依赖NO的机制在麻醉大鼠中引发胰岛素分泌。本研究的目的是评估静脉输注葡萄糖时的胰岛素分泌反应是否也需要完整的NO生成。给麻醉大鼠静脉注射D-葡萄糖（100 mg·kg⁻¹·min⁻¹，持续30分钟）。在输注结束前及结束后15分钟评估血浆胰岛素（PI）、血糖（BG）水平和平均动脉血压（MAP）。一组大鼠未接受处理作为对照。另外两组大鼠分别用一氧化氮合酶抑制剂Nω-硝基-L-精氨酸甲酯（L-NAME，50 mg·kg⁻¹静脉注射）或N⁰-甲基-L-精氨酸（L-NMMA，100 mg·kg⁻¹静脉注射）进行预处理。在对照组中，输注葡萄糖使PI升高多达25±3 U·L⁻¹，BG升高多达27±1 mmol·L⁻¹。用L-NAME预处理使MAP从74±6 mmHg升高至132±4 mmHg，表明一氧化氮合酶被抑制。（摘要截断于250字）
