1 Department of Animal Science, Texas A&M University, College Station, TX 77843-2471, USA.
2 Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843-2471, USA.
Exp Biol Med (Maywood). 2018 Mar;243(6):525-533. doi: 10.1177/1535370218758275. Epub 2018 Feb 22.
Maternal nutrition during gestation, especially dietary protein intake, is a key determinant in embryonic survival, growth, and development. Low maternal dietary protein intake can cause embryonic losses, intra-uterine growth restriction, and reduced postnatal growth due to a deficiency in specific amino acids that are important for cell metabolism and function. Of note, high maternal dietary protein intake can also result in intra-uterine growth restriction and embryonic death, due to amino acid excesses, as well as the toxicity of ammonia, homocysteine, and HS that are generated from amino acid catabolism. Maternal protein nutrition has a pronounced impact on fetal programming and alters the expression of genes in the fetal genome. As a precursor to the synthesis of molecules (e.g. nitric oxide, polyamines, and creatine) with cell signaling and metabolic functions, L-arginine (Arg) is essential during pregnancy for growth and development of the conceptus. With inadequate maternal dietary protein intake, Arg and other important amino acids are deficient in mother and fetus. Dietary supplementation of Arg during gestation has been effective in improving embryonic survival and development of the conceptus in many species, including humans, pigs, sheep, mice, and rats. Both the balance among amino acids and their quantity are critical for healthy pregnancies and offspring. Impact statement This review aims at: highlighting adverse effects of elevated levels of ammonia in mother or fetus on embryonic/fetal survival, growth, and development; helping nutritionists and practitioners to understand the mechanisms whereby elevated levels of ammonia in mother or fetus results in embryonic/fetal death, growth restriction, and developmental abnormalities; and bringing, into the attention of nutritionists and practitioners, the problems of excess or inadequate dietary intake of protein or amino acids on pregnancy outcomes in animals and humans. The article provides new, effective means to improve embryonic/fetal survival and growth in mammals.
母体在妊娠期间的营养，特别是饮食蛋白质的摄入，是胚胎存活、生长和发育的关键决定因素。母体饮食蛋白质摄入不足会导致胚胎死亡、宫内生长受限和产后生长减少，这是由于细胞代谢和功能所需的特定氨基酸的缺乏。值得注意的是，由于氨基酸过量以及氨基酸分解产生的氨、同型半胱氨酸和 HS 的毒性，高母体饮食蛋白质摄入也会导致宫内生长受限和胚胎死亡。母体蛋白质营养对胎儿编程有显著影响，并改变胎儿基因组中的基因表达。作为具有细胞信号和代谢功能的分子（如一氧化氮、多胺和肌酸）合成的前体，L-精氨酸（Arg）在妊娠期间对于胚胎的生长和发育至关重要。由于母体饮食蛋白质摄入不足，Arg 和其他重要氨基酸在母体和胎儿中都缺乏。在许多物种（包括人类、猪、羊、老鼠和大鼠）中，妊娠期 Arg 饮食补充已被证明能有效提高胚胎存活率和胚胎发育。氨基酸的平衡及其数量对于健康的妊娠和后代都至关重要。 影响声明 本综述旨在：强调母体或胎儿中氨水平升高对胚胎/胎儿存活、生长和发育的不良影响；帮助营养学家和从业者了解母体或胎儿中氨水平升高导致胚胎/胎儿死亡、生长受限和发育异常的机制；并引起营养学家和从业者对动物和人类蛋白质或氨基酸的饮食摄入过多或不足对妊娠结局的关注。本文为改善哺乳动物胚胎/胎儿存活和生长提供了新的、有效的方法。
