Brockman R P, Laarveld B
Can J Physiol Pharmacol. 1986 Aug;64(8):1055-9. doi: 10.1139/y86-181.
Owing to the fermentative nature of their digestion, ruminant animals are highly dependent upon gluconeogenesis to meet their glucose needs. The role of hormones in regulating this process is not clear. The purpose of this study was to examine the effect of insulin on the utilization of lactate in glucose synthesis in sheep. The euglycemic model was used in sheep. [U-14C]Lactate and [6-3H]glucose were infused to monitor lactate and glucose fluxes. Hepatic metabolism was measured using radioisotopic and venoarterial concentration difference techniques. Insulin concentrations increased from basal concentrations of 16 +/- 2 to 95 +/- 9 microU/mL. Insulin reduced the net hepatic utilization of lactate (303 +/- 43 vs. 120 +/- 27 mumol/min), hepatic extraction efficiency of lactate (29 +/- 4 vs. 9 +/- 2%), hepatic output of glucose (338 +/- 33 vs. 103 +/- 21 mumol/min), and incorporation of lactate into glucose (90 +/- 5 vs. 46 +/- 8 mumol/min). Insulin at physiological levels can inhibit hepatic gluconeogenesis in ruminants.
由于反刍动物消化过程具有发酵特性，它们高度依赖糖异生来满足对葡萄糖的需求。激素在调节这一过程中的作用尚不清楚。本研究的目的是检测胰岛素对绵羊葡萄糖合成中乳酸利用的影响。在绵羊中采用了正常血糖模型。输注[U-14C]乳酸和[6-3H]葡萄糖以监测乳酸和葡萄糖通量。使用放射性同位素和静脉-动脉浓度差技术测量肝脏代谢。胰岛素浓度从基础浓度16±2微单位/毫升增加到95±9微单位/毫升。胰岛素降低了肝脏对乳酸的净利用（303±43对120±27微摩尔/分钟）、肝脏对乳酸的提取效率（29±4对9±2%）、肝脏葡萄糖输出（338±33对103±21微摩尔/分钟）以及乳酸掺入葡萄糖的量（90±5对46±8微摩尔/分钟）。生理水平的胰岛素可抑制反刍动物的肝脏糖异生。
