Department of Animal Science, Texas A&M University, College Station, TX 77843-2471, USA.
Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843-4458, USA.
Exp Biol Med (Maywood). 2023 Apr;248(8):702-711. doi: 10.1177/15353702231157943. Epub 2023 Apr 3.
This study was conducted with gilts as an animal model to test the hypothesis that dietary supplementation with L-citrulline (Cit) improves placental angiogenesis and embryonic survival. Between Days 14 and 25 of gestation, each gilt was fed a corn- and soybean-meal-based diet (2 kg/day) supplemented with 0.4% Cit or an isonitrogenous amount of L-alanine (Control). On Day 25 of gestation, gilts were hysterectomized to obtain conceptuses. Amniotic and allantoic fluids and placentae were analyzed for NOx [stable oxidation products of nitric oxide (NO)], polyamines, and amino acids (AAs). Placentae were also analyzed for syntheses of NO and polyamines; concentrations of AAs and related metabolites; and the expression of angiogenic factors and aquaporins (AQPs). Compared to the control group, Cit supplementation increased ( < 0.01) the number of viable fetuses by 2.0 per litter, the number and diameter of placental blood vessels (21% and 24%, respectively), placental weight (15%), and total allantoic and amniotic fluid volumes (20% and 47%, respectively). Cit supplementation also increased ( < 0.01) enzymatic activities of GTP-cyclohydrolase-1 (32%) and ornithine decarboxylase (27%) in placentae; syntheses of NO (29%) and polyamines (26%); concentrations of NOx (19%), tetrahydrobiopterin (28%), polyamines (22%), cAMP (26%), and cGMP (24%) in placentae; total amounts of NOx (22-40%), polyamines (23-40%), AAs (16-255%), glucose (22-44%), and fructose (22-43%) in allantoic and amniotic fluids. Furthermore, Cit supplementation increased ( < 0.05) placental mRNA levels for angiogenic factors ( [84%], [55%], [61%], [26%], and [137%], as well as AQPs - AQP1 [105%], AQP3 [53%], AQP5 [77%], AQP8 [57%], and AQP9 [31%]). Collectively, dietary Cit supplementation enhanced placental NO and polyamine syntheses as well as angiogenesis to improve conceptus development and survival.
本研究以母猪为动物模型，旨在验证日粮补充 L-瓜氨酸（Cit）是否可以改善胎盘血管生成和胚胎存活率这一假说。在妊娠第 14 天至第 25 天期间，每头母猪每天喂食 2 公斤基于玉米和大豆的日粮（玉米-豆粕型日粮），并额外添加 0.4%的 Cit 或等氮量的 L-丙氨酸（对照组）。在妊娠第 25 天，母猪被进行子宫切除术以获取胚胎。分析羊水和胎盘中的硝酸盐（NO 的稳定氧化产物）、多胺和氨基酸（AAs）。还分析了胎盘的 NO 和多胺合成；AAs 和相关代谢物的浓度；以及血管生成因子和水通道蛋白（AQPs）的表达。与对照组相比，Cit 补充增加了（ < 0.01）每个窝产仔数 2.0 头，胎盘血管数量（分别增加 21%和 24%）、胎盘重量（增加 15%）以及总羊水和胎尿体积（分别增加 20%和 47%）。Cit 补充还增加了（ < 0.01）胎盘 GTP-环水解酶-1（32%）和鸟氨酸脱羧酶（27%）的酶活性；NO（29%）和多胺（26%）的合成；胎盘硝酸盐（19%）、四氢生物蝶呤（28%）、多胺（22%）、cAMP（26%）和 cGMP（24%）的浓度；总硝酸盐（22-40%）、多胺（23-40%）、AAs（16-255%）、葡萄糖（22-44%）和果糖（22-43%）的胎尿和胎盘中的含量。此外，Cit 补充增加了（ < 0.05）胎盘血管生成因子的 mRNA 水平（ [84%]， [55%]， [61%]， [26%]，和 [137%]）以及水通道蛋白（AQPs）-AQP1 [105%]、AQP3 [53%]、AQP5 [77%]、AQP8 [57%]和 AQP9 [31%]）。总之，日粮补充 Cit 可增强胎盘 NO 和多胺的合成以及血管生成，从而改善胚胎的发育和存活率。
