Buchanan T A
Department of Medicine, University of Southern California Medical School, Los Angeles 90033.
Isr J Med Sci. 1991 Aug-Sep;27(8-9):432-41.
A remarkably coordinated set of metabolic adaptations allows the intermittently feeding mother to provide not only for her own energy needs, but also for those of the continuously feeding and developing fetus. During feeding, progressive insulin resistance and compensatory hyperinsulinemia appear to promote storage of nutrients in maternal fat and serve to "shunt" nutrients to the fetus by slowing their uptake into maternal tissues, especially during late pregnancy. Between feedings, hormones liberated by the fetoplacental unit create an environment that progressively favors maternal fat catabolism as an energy substrate source, thus curbing maternal protein catabolism while keeping some carbohydrate available for the fetus. These normal changes have important implications for women with abnormal glucoregulation. Women with pre-gestational diabetes will need progressively greater insulin doses during gestation in order to maintain normoglycemia and, in the case of women with IDDM, to avoid ketosis. Women without known diabetes may develop glucose intolerance by late gestation if their pancreatic B cells are not capable of compensating for their inherent insulin resistance and/or the normal insulin resistance of pregnancy. Norbert Freinkel was a leader in the development of our current physiological understanding of these metabolic adaptations to pregnancy. That understanding has contributed greatly to the improved outcome of pregnancies complicated by maternal diabetes. A major challenge for present and future investigators will be to develop an understanding of those adaptations at the molecular and genetic levels so that we may have even greater impact on the well-being of diabetic women and their offspring.
一系列显著协调的代谢适应机制使间歇性进食的母亲不仅能够满足自身的能量需求，还能满足持续进食和发育中的胎儿的能量需求。在进食期间，逐渐出现的胰岛素抵抗和代偿性高胰岛素血症似乎促进了母体脂肪中营养物质的储存，并通过减缓营养物质进入母体组织的速度，将营养物质“分流”给胎儿，尤其是在妊娠晚期。在两次进食之间，胎儿-胎盘单位释放的激素营造了一种环境，这种环境逐渐有利于将母体脂肪分解代谢作为能量底物来源，从而抑制母体蛋白质分解代谢，同时为胎儿保留一些碳水化合物。这些正常变化对血糖调节异常的女性具有重要意义。患有孕前糖尿病的女性在妊娠期间需要逐渐增加胰岛素剂量，以维持血糖正常，对于患有胰岛素依赖型糖尿病的女性来说，还要避免酮症。如果胰腺β细胞无法补偿其自身固有的胰岛素抵抗和/或妊娠正常的胰岛素抵抗，妊娠晚期未患糖尿病的女性可能会出现糖耐量异常。诺伯特·弗赖因克尔在我们目前对妊娠代谢适应的生理学理解的发展过程中起到了引领作用。这种理解极大地改善了患有母体糖尿病的妊娠结局。当前和未来的研究人员面临的一个主要挑战将是在分子和基因水平上理解这些适应机制，以便我们能够对糖尿病女性及其后代的健康产生更大影响。
