Rémésy C, Demigné C
J Dev Physiol. 1986 Jun;8(3):195-205.
The relative importance of the main glucogenic and ketogenic substrates, and interactions between fatty acids availability and ketogenesis have been investigated in virgin or 21 day pregnant rats. Fed pregnant rats displayed elevated lactatemia and the production of lactate by portal-drained viscera was markedly reduced. In contrast, the production of alanine and propionate from digestion was almost similar in fed pregnant and virgin rats. The release of glucose by the liver in fed animals was higher in pregnant rats, and lactate was the main glucogenic substrate taken up whereas alanine uptake was reduced. The hepatic utilization of propionate was not different between the two groups of fed animals. Hepatic gluconeogenesis and lactate extraction were enhanced by starvation; the contribution of lactate to glucose release remained higher in pregnant than in virgin rats, whereas the contribution of alanine was lower, owing to its decreased availability in afferent blood. There was a large uptake of intestinally-derived acetate in fed rates, and a slight release, parallel to ketogenesis, was observed in starved pregnant rats. Free fatty acids were elevated and efficiently taken up by the liver in fed pregnant rats, but without any noticeable ketogenesis. Hepatic ketogenesis was enhanced in starved animals, with marked hyperketonaemia in pregnant rats. However, in those animals, the hepatic release of ketone bodies was not proportional to ketonaemia and was almost similar to the release in starved virgin rats.
在未孕或妊娠21天的大鼠中，研究了主要生糖和生酮底物的相对重要性，以及脂肪酸可用性与酮体生成之间的相互作用。喂食后的妊娠大鼠出现乳酸血症升高，门静脉引流内脏产生乳酸的量显著减少。相反，喂食后的妊娠大鼠和未孕大鼠消化产生丙氨酸和丙酸的量几乎相似。喂食动物中，妊娠大鼠肝脏释放葡萄糖的量更高，乳酸是肝脏摄取的主要生糖底物，而丙氨酸的摄取减少。两组喂食动物肝脏对丙酸的利用没有差异。饥饿会增强肝脏糖异生和乳酸摄取；与未孕大鼠相比，妊娠大鼠中乳酸对葡萄糖释放的贡献仍然更高，而丙氨酸的贡献更低，这是由于其在传入血液中的可用性降低。喂食的大鼠对肠道来源的乙酸盐有大量摄取，饥饿的妊娠大鼠中观察到与酮体生成平行的少量释放。喂食的妊娠大鼠中游离脂肪酸升高，肝脏有效摄取，但没有明显的酮体生成。饥饿动物的肝脏酮体生成增强，妊娠大鼠出现明显的高酮血症。然而，在这些动物中，肝脏酮体的释放与酮血症不成比例，几乎与饥饿的未孕大鼠的释放相似。
