Effect of p53-gene expression on renal function in rat with low birth weight

Abstract

Objective To investigate the effect of p53-gene expression on renal function in rat with low birth weight (LBW). Methods Fifteen pregnant rats were randomly assigned into normal group, LBW group, and L-arginine (L-Arg)-treated group. For normal group, pregnant rats were fed with 21% protein diet during pregnancy. For LBW and L-Arg treated groups, rats were fed with 10% protein diet. After delivery, all rats were fed with 21% protein diet. For L-Arg-treated group, rats were given a supplementation with L-Arg (200 mg/kg) drinking water during 21 d lactation, other rats were given running water. At the age of 2m, the ultrastructural change in mesangial cell and podocyte was observed with electron microscope. At the age of 7 d, 21 d, 2 m, and 3 m old, the p53 mRNA expression in renal tissues was observed with reverse transcription polymerase chain reaction (RT-PCR), blood and urine were collected to detect biochemical indicators of renal function and 24 h-urine protein. Results ⑴ At the age of 3 m, the blood urea nitrogen (BUN) and urine cretinine (UCr) in normal group were significantly lower than those in LBW group (P<0.01). Compared to normal group, the Ucr of LBW group was significantly lower at the age of 2 m (P<0.05). At the age of 3 m, the Ucr of L-Arg treated group and LBW group was significantly lower (P<0.05), the level of 24 h-Urine protein was notably increased in LBW group and L-Arg treated group than that in normal group (P<0.01, P<0.05). ⑵ At the age of 3 m, the expression of p53 mRNA in LBW group was higher obviously than that in normal group. There is a significantly negative correlation between the expression of p53 mRNA and the level of Ucr in LBW group (r=-0.91, P<0.05). ⑶ There were mesangial cell proliferation with matrix increase, filtration membrane podocyte reduction, and partially dissolved in LBW group, the mesangial cell proliferation of L-Arg treated group was decreased compared to that in LBW group. Conclusions The higher expression of p53 gene in LBW group might be one of reasons for the decreased renal function in LBW rats. Key words: Genes, p53; Birth weight; Kidney/ME/PA