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 de-livery, 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 re-verse transcription polymerase chain reaction ( RT-PCR) , blood and urine were collected to detect biochem-ical indicators of renal function and 24 h-urine protein.Results ⑴At the age of 3 m,the blood urea nitro-gen ( 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) .⑵At 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 dis-solved 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.
ABSTRACT
Objective To study the effect of renal p53 protein expression on kidney development in rats with intrauterine growth restriction ( IUGR) . Methods Pregnant rats were randomly assigned into normal group, IUGR group and L-Arg treated group. Normal group were fed with normal diet (21％protein). IUGR group and L-Arg treated group were fed with low-protein diet (10％ protein). During lactation, maternal rats in the three groups were all fed with normal diet. Maternal rats in L-Arg treated group were given additional special drinking water ( L-Arg:200 mg/kg) , while maternal rats in normal and IUGR group were given normal drinking water. Offspring weaned after 21 d and had free access to normal rodent diet and water. When the pups grew up to 2 m, the number of glomeruli was counted using acid digestion method, the proliferation and apoptosis of glomerular and tubular cells were studied using TUNEL and Ki-67 immunohistochemistry, and the ultrastructure of epithelial cells was determined by electron microscopy. At 7 d, 21 d, 2 m and 3 m, p53 protein expression in renal tissue was measured by Western blot, respectively. Results At 2 m, the number of glomerulus ( right kidney) in IUGR group was significantly lower than normal group [(23 647±541) vs. (27 689±492), P＜0. 01]; the index of renal cell apoptosis in IUGR group was higher than normal group [(21. 9 ± 2. 0) vs. (16. 7 ± 2. 5), P＜0. 05];however, IUGR group and normal group had no statistically significant difference (P＞0. 05). The proliferation of mesangial cells was found in IUGR and L-Arg treated group, but not in normal group. And the extent of proliferation in L-Arg treated group was lesser than IUGR group. A reduction of foot process and partial fusion of foot process could be observed in IUGR group and L-Arg treated group while the foot process morphology in normal group was normal. At 2 m and 3 m, p53 protein level in IUGR group and L-Arg treated group were higher than normal group [ 2 m: ( 0. 28 ± 0. 03 ) and ( 0. 21 ± 0. 01 ) vs. (0. 10±0. 02);3 m:(0. 39±0. 04) and (0. 26±0. 02) vs. (0. 17±0. 03);P＜0. 01], while IUGR group higher than L-Arg treated group ( P＜0. 05 ) . Conclusions The kidney of IUGR rats showed reduced glomerular number, increased renal cell apoptosis, enhanced p53 protein expression, increased proliferation of glomerular mesangial cells, decreased foot process, and partial fusion of foot process. And L-Arg could to some extent improve the organizational structure of the kidney in IUGR rats.
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To study the changes in skeletal muscle structure and insulin resistance of low birth weight rats.The low birth weight filial rat model was established by feeding low protein diet to the pregnant rat during gestation.At 7 d,21 d,and 2 months,blood glucose and serum insulin were measured,and the structure of skeletal muscle was observed.From 7 d to 2 months,the muscle fibers of low birth weight rat were atrophic and arranged in disorder.The ultrastructure of skeletal muscle was also abnormal distinctly at 2 months.No differences of blood glucose and rerum insulin were found between the two groups.
ABSTRACT
Objective To observe the influence of L-Arg supplementation during early postnatal life on renal function of rats with intrauterine growth retardation(IUGR).Mehod Afer establishment of IUGR model with 10% protein diet,rats were divided randomly into 2 groups: IUGR group and L-Arg treated group(LT group).Normal control group(NC group) rats were fed with 20% protein diet.The level of NO,Cr in serum were measured from 1 w to 3 months and UCr,24 h-proteinuria were measured from 3 w to 3 months.Results(1)The levels of serum NO reduced significantly in group IUGR at every stage,not significantly different between group LT and NC,but more in group LT than in group IUGR.(2)The levels of 24h-proteinuria had no significant difference among three groups at 3 w and 2 month,but was significantly higher in group IUGR than group LT and group NC.(3)The Cr levels had no significant difference at every stage among three groups.The UCr level was decreased in group IUGR than group NC at 2 month and than group NC and LT at 3 month.(4)The level of CCr in group IUGR was decreased significantly at 3 w,2 month and 3 month than group LT and group NC.Conclusion L-Arg can increase serum NO and CCr levels and decrease the level of 24h-proteinuria in rats with IUGR.It is one of the important reasons to increase 24h-proteinuria and reduce CCr level for low NO value.