Topping D L, Storer G B, Trimble R P
Division of Human Nutrition, Commonwealth Scientific and Industrial Research Organization, O'Halloran Hill, Australia.
Am J Physiol. 1988 Sep;255(3 Pt 1):E306-13. doi: 10.1152/ajpendo.1988.255.3.E306.
In rat livers perfused with undiluted rat blood at perfusion rates of 6, 12, or 18 ml/min, hepatic O2 consumption rose with blood flow. Lipogenesis was unaffected by blood flow in control livers and was enhanced by insulin at 12 and 18 ml/min. Very-low-density lipoprotein triacylglycerol secretion also rose with increased flow and was stimulated by insulin at both 6 and 12 ml/min. When glucose was added to livers perfused at 12 or 18 ml/min, uptake was independent of perfusion rate and was slightly stimulated by insulin. Total lipogenesis and the secretion of newly synthesized fatty acids in very-low-density lipoprotein triacylglycerols were unaffected by insulin at either flow rate. The hormone stimulated triacylglycerol secretion at 18 ml/min but inhibited it at 12 ml/min. It seems that in perfused liver, effects of insulin on lipogenesis and very-low-density lipoprotein secretion may be modified not only by changes in O2 consumption (in this case through alterations in blood flow) but also by the choice of substrate.
在以6、12或18毫升/分钟的灌注速率用未稀释的大鼠血液灌注的大鼠肝脏中，肝脏耗氧量随血流增加而升高。在对照肝脏中，脂肪生成不受血流影响，而在12和18毫升/分钟时，胰岛素可增强脂肪生成。极低密度脂蛋白三酰甘油分泌也随血流增加而升高，在6和12毫升/分钟时均受到胰岛素刺激。当向以12或18毫升/分钟灌注的肝脏中添加葡萄糖时，葡萄糖摄取与灌注速率无关，且受到胰岛素的轻微刺激。在任一灌注速率下，胰岛素均不影响总脂肪生成以及极低密度脂蛋白三酰甘油中新合成脂肪酸的分泌。该激素在18毫升/分钟时刺激三酰甘油分泌，但在12毫升/分钟时抑制其分泌。似乎在灌注肝脏中，胰岛素对脂肪生成和极低密度脂蛋白分泌的影响不仅可能因耗氧量的变化（在这种情况下是通过血流改变）而改变，还可能因底物的选择而改变。
