Dietary rumen-protected L-arginine or N-carbamylglutamate enhances placental amino acid transport and suppresses angiogenesis and steroid anabolism in underfed pregnant ewes

Hao Zhang; Xia Zha; Bei Zhang; Yi Zheng; Xiaoyun Liu; Mabrouk Elsabagh; Yi Ma; Hongrong Wang; Guihua Shu; Mengzhi Wang

doi:10.1016/j.aninu.2023.08.005

Dietary rumen-protected L-arginine or N-carbamylglutamate enhances placental amino acid transport and suppresses angiogenesis and steroid anabolism in underfed pregnant ewes

Anim Nutr. 2023 Aug 22:15:149-158. doi: 10.1016/j.aninu.2023.08.005. eCollection 2023 Dec.

Authors

Hao Zhang^{1

2}, Xia Zha^{1

2}, Bei Zhang^{1

2}, Yi Zheng^{1

2}, Xiaoyun Liu^{1

2}, Mabrouk Elsabagh^{3

4}, Yi Ma^{1

2}, Hongrong Wang^{1

2}, Guihua Shu^{1

5}, Mengzhi Wang^{1

2}

Affiliations

¹ Laboratory of Metabolic Manipulation of Herbivorous Animal Nutrition, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China.
² Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China.
³ Department of Animal Production and Technology, Faculty of Agricultural Sciences and Technologies, Niğde Ömer Halisdemir University, Nigde 51240, Turkey.
⁴ Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Kafrelsheikh University, KafrelSheikh, Egypt.
⁵ Department of Pediatrics, Northern Jiangsu People's Hospital, Clinical Medical College, Yangzhou University, Yangzhou 225001, China.

Abstract

This study aimed to investigate the effects of dietary supplementation of underfed Hu ewes from d 35 to 110 of gestation with either rumen-protected L-arginine (RP-Arg) or N-carbamylglutamate (NCG) on placental amino acid (AA) transport, angiogenic gene expression, and steroid anabolism. On d 35 of gestation, 32 Hu ewes carrying twin fetuses were randomly divided into four treatment groups, each consisting of eight ewes, and were fed the following diets: A diet providing 100% of NRC's nutrient requirements for pregnant ewes (CON); A diet providing 50% of NRC's nutrient requirements for pregnant ewes (RES); RES diet plus 5 g/d NCG (RES + NCG); or RES diet plus 20 g/d RP-Arg (RES + ARG). On the d 110 of pregnancy, blood samples were taken from the mother, and samples were collected from type A cotyledons (COT; the fetal portions of the placenta). The levels of 17β-estradiol and progesterone in the maternal serum and both the capillary area density (CAD) and capillary surface density (CSD) in type A COT were decreased in response to Arg or NCG supplementation when compared to the RES group. The concentrations of arginine, leucine, putrescine and spermidine in type A COT were higher (P < 0.05) in the RES + ARG or RES + NCG group than in the RES group. The mRNA expression levels of inducible nitric oxide synthase (iNOS) and solute carrier family 15, member 1 (SLC15A1) were increased (P < 0.05) while those of progesterone receptor (PGR) and fibroblast growth factor 2 (FGF2) were decreased in type A COT by supplementation with either NCG or RP-Arg compared to the RES group. The results suggest that providing underfed pregnant ewes from d 35 to 110 of gestation with a diet supplemented with NCG or RP-Arg improves placental AA transport, and reduces the expression of angiogenic growth factor genes and steroid anabolism, leading to better fetal development.

Keywords: Angiogenesis factor; L-arginine; N-carbamylglutamate; Placental amino acid transport; Pregnant ewes; Steroid anabolism.