Effect of L-arginine supplementation on the hepatic phosphatidylinositol 3-kinase signaling pathway and gluconeogenic enzymes in early intrauterine growth-restricted rats

Abstract

Abstract. The present study aimed to investigate the response of the phosphatidylinositol 3-kinase (PI3K) signaling pathway and gluconeogenic enzymes in intrauterine growth-restricted rats to dietary L-arginine (L-Arg) supplementation during the lactation period early in life. Pregnant Sprague-Dawley rats were randomly divided into a control group (CON), an intrauterine growth restriction group (IUGR) and an L-Arg group (LA). The pregnant rats in the CON group were fed a 21% protein diet, and those in the IUGR and LA groups were fed a 10% low protein diet, and all rats were fed a 21% protein diet after delivery. Water was available ad libitum to the pregnant rats during the 21-day lactation period, and the water provided to the LA group included 200 mg/kg/day L-Arg. Blood glucose, serum insulin, homeostasis model of assessment for insulin resistance (HOMA-IR), PI3K and protein kinase B (PKB) protein expression, and phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G-6-Pase) mRNA expression in the offspring rats were measured postnatally at 1, 3 and 8 weeks. No significant difference in blood glucose, serum insulin and HOMA-IR were identified at any time point among the three groups. PI3K and PKB expression was lower in the IUGR group offspring compared with that in the CON group offspring, but both were increased by dietary L-Arg supplementation. PEPCK mRNA and G-6-Pase mRNA expression levels in the offspring of the IUGR group were higher compared with those in the CON group but were downregulated following L-Arg supplementation. These results suggest that dietary L-Arg supplementation during the early lactation period promoted catch-up growth and reversed abnormalities in hepatic insulin signaling and gene expression of gluconeogenic enzymes in IUGR offspring rats.

Hypoglycemic and Hypolipidemic Activity of Arginine Containing Bearberry Leaves Extract in Insulin Resistant Rats

“…The arginine administration is known to stimulate the expression of PI3K and Akt which entails an increase in the sensitivity of cells to insulin [15]. This evidence found the confirmation in our current experiment.…”

Gossypol from Cottonseeds Ameliorates Glucose Uptake by Mimicking Insulin Signaling and Improves Glucose Homeostasis in Mice with Streptozotocin‐Induced Diabetes

“…Normally, insulin can mitigate gluconeogenesis through multiple mechanisms. One such mechanism is the direct inhibition of the transcription of key gluconeogenic genes, such as PEPCK and G6Pase, by blocking the recruitment of the transcriptional coactivators PGC-1 α and CREB-binding protein to the promoters of the PEPCK and G6Pase genes [ 38 ]. In the current study, GSP reduced the expressions of PEPCK and G6Pase in the liver compared to the STZ-induced diabetic control group ( Figure 7(e) ).…”

Dietary Supplementation of L-Arginine and N-Carbamylglutamate Attenuated the Hepatic Inflammatory Response and Apoptosis in Suckling Lambs with Intrauterine Growth Retardation

“…Maternal nutrition of L-arginine (L-Arg), a semiessential amino acid, and its precursor N-carbamylglutamate (NCG) during pregnancy has been shown to mitigate the IUGRmetabolic disruptions in ovine fetus [18][19][20][21] and rat offspring [22] and enhance fetal development and neonatal survival and growth in mammals [23][24][25]. Also, L-Arg and NCG have been shown to protect the liver against lipid peroxidation [26][27][28] as well as play a key role in inflammatory response regulation [29].…”