Dietary arginine supplementation during early pregnancy enhances embryonic survival in rats.
Four experiments were conducted with 120 pregnant Sprague-Dawley rats to determine effects of dietary arginine supplementation on embryonic survival. Rats were fed a nonpurified diet supplemented with 1.3% (wt:wt) L-arginine-HCl or 2.2% (wt:wt) L-alanine (isonitrogenous control) throughout pregnancy (Expt. 1), between d 1 and 7 of gestation and then the nonpurified diet until parturition (Expt. 2), between d 1 and 7 of gestation for determining the number of surviving embryos on d 7 (Expt. 3), or between d 1 and 4 of pregnancy for blood sampling on d 5 after overnight food deprivation (Expt. 4). Litter size increased (P < 0.01) in response to arginine supplementation throughout pregnancy (14.5 +/- 0.62 vs. 11.3 +/- 0.61) or during the first 7 d of pregnancy (14.7 +/- 0.33 vs. 11.3 +/- 0.37). The number of surviving embryos was greater (P < 0.01) when arginine was supplemented between d 1 and 7 of pregnancy (14.7 +/- 0.39 vs. 11.4 +/- 0.66). Concentrations of nitric-oxide metabolites, arginine, proline, glutamine, and ornithine were higher (P < 0.05), but urea levels were lower (P < 0.05) in the serum of arginine-supplemented rats compared with the control group. The arginine treatment increased (P < 0.05) protein levels for inducible and constitutive nitric-oxide synthase at implantation sites by 35-37%. These results indicate that dietary arginine supplementation enhances embryonic survival, therefore increasing litter size by 30% at term birth. This novel finding has important implications for preventing early pregnancy loss and enhancing reproductive performance in mammals.
Zeng
Xiangfang
X
State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, China 100094.
Wang
Fenglai
F
Fan
Xia
X
Yang
Wenjun
W
Zhou
Bo
B
Li
Pengfei
P
Yin
Yulong
Y
Wu
Guoyao
G
Wang
Junjun
J
D000409:Alanine / Q000494:pharmacology; D000596:Amino Acids / Q000097:blood / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000008:administration & dosage* / Q000494:pharmacology; D004032:Diet; D019587:Dietary Supplements; D010064:Embryo Implantation / Q000187:drug effects; D020964:Embryo Loss / Q000517:prevention & control*; D005260:Female; D008098:Litter Size / Q000187:drug effects; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012098:Reproduction / Q000187:drug effects
D000596:Amino Acids; D001120:Arginine; D000409:Alanine