Dietary N-carbamylglutamate or L-arginine supplementation improves hepatic energy status and mitochondrial function and inhibits the AMP-activated protein kinase- peroxisome proliferator-activated receptor γ coactivator-1α-transcription factor A pathway in intrauterine-growth-retarded suckling lambs

The objective of this study was to investigate the effects of dietary administration of L-arginine (Arg) or N-carbamylglutamate (NCG) on hepatic energy status and mitochondrial functions in suckling Hu lambs with intrauterine growth retardation (IUGR). Forty-eight newborn Hu lambs of 7 d old were allocated into 4 treatment groups of 12 lambs each, in triplicate with 4 lambs per replicate (2 males and 2 females) as follows: CON (lambs of normal birth weight, 4.25 +/- 0.14 kg), IUGR (3.01 +/- 0.12 kg), IUGR thorn 1% Arg (2.99 +/- 0.13 kg), or IUGR thorn 0.1% NCG (3.03 +/- 0.11 kg). The experiment lasted for 21 d, until d 28 after birth, and all lambs were fed milk replacer as a basal diet. Compared with IUGR lambs, NCG or Arg administration increased (P < 0.05) the adenosine triphosphate (ATP) level and the activities of complexes I/III/IV, isocitrate dehydrogenase and citrate synthase in the liver. Compared with CON lambs, the relative mRNA levels of adenosine monophosphate-activated protein kinase alpha 1 (AMPK alpha 1), peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC1 alpha) and transcription factor A (TFAM) were increased (P < 0.05) in the liver of IUGR lambs, but were decreased (P < 0.05) in the liver of NCG- or Arg-treated lambs compared with those in the IUGR lambs. Compared with IUGR lambs, NCG or Arg administration decreased (P < 0.05) the total AMPK alpha (tAMPK alpha)-to-phosphorylated AMPK alpha (pAMPK alpha) ratio and the protein expression of PGC1a alpha and TFAM. The results suggested that dietary Arg or NCG supplements improved hepatic energy status and mitochondrial function and inhibited the AMPK-PGC1 alpha-TFAM pathway in IUGR suckling lambs. (C) 2021 Chinese Association of Animal Science and Veterinary Medicine. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.

Automated summary

The study showed that dietary supplementation of L-arginine (Arg) or N-carbamylglutamate (NCG) improved hepatic energy status and mitochondrial function in suckling Hu lambs with intrauterine growth retardation (IUGR) and inhibited the AMPK-PGC1α-TFAM pathway.