Ramsay T G, Sheahan J A, Martin R J
Am J Physiol. 1984 Nov;247(5 Pt 2):R755-60. doi: 10.1152/ajpregu.1984.247.5.R755.
The present experiment was conducted to determine whether lactate is an important metabolic substrate for the developing porcine placenta. Pregnant gilts were anesthetized with pentobarbital sodium (5 mg/kg) at 65, 85, or 110 days of gestation and underwent an abdominohysterectomy. Fetal and maternal placental tissues were obtained and isolated for enzyme analysis and tissue incubations. Tissues were incubated for 2 h in Krebs-Ringer bicarbonate buffer containing 10 mM glucose, 1.0 mM Na-palmitate, 2.0 mM L-lactate, and 2% albumin. The incorporation of glucose or lactate into CO2, total lipids, and fatty acids was examined by radioactive tracers. Lactate was shown to be at least as important a substrate as glucose for utilization through these metabolic pathways in both the fetal and maternal placentas during gestation. This ability to metabolize lactate may serve as a conservation mechanism to spare other nutrients for transfer to the fetus. Additionally, analysis of enzyme and incubation data indicated that the fetal and maternal placenta follow different developmental patterns, implying the origins for (or mechanisms of) regulation of these two tissues may differ.
本实验旨在确定乳酸是否为发育中的猪胎盘的重要代谢底物。在妊娠65、85或110天时，用戊巴比妥钠（5毫克/千克）对怀孕的后备母猪进行麻醉，然后进行腹式子宫切除术。获取胎儿和母体的胎盘组织并分离，用于酶分析和组织培养。将组织在含有10毫摩尔葡萄糖、1.0毫摩尔棕榈酸钠、2.0毫摩尔L-乳酸和2%白蛋白的 Krebs-Ringer 碳酸氢盐缓冲液中培养2小时。通过放射性示踪剂检测葡萄糖或乳酸掺入二氧化碳、总脂质和脂肪酸的情况。结果表明，在妊娠期间，乳酸作为底物在胎儿和母体胎盘中通过这些代谢途径被利用的重要性至少与葡萄糖相当。这种代谢乳酸的能力可能是一种保护机制，以节省其他营养物质用于转运给胎儿。此外，酶分析和培养数据表明胎儿和母体胎盘遵循不同的发育模式，这意味着这两种组织的调节起源（或机制）可能不同。
