Abstract:

ＯｂｊｅｃｔｉｖｅTo investigate the effect of p21WAF1/CIP1/SDI1 on the renal lesions in aging kidneys in rats. ＭｅｔｈｏｄｓMale Wistar rats at the ages of 3, 12, 24 months were used in this study. The renal tissues were processed for senescence associated βgalactosidase (SAβgal) staining. TUNEL assay was used to detect apoptosis of renal tubular epithelial cells. The expression and location of p21WAF1/CIP1/SDI1 in kidneys were studied by immunohistochemistry. The mRNA and protein levels of p21WAF1/CIP1/SDI1 were detected by Western blot and RTPCR, respectively. ＲｅｓｕｌｔｓThe expression of neutral βgalactosidase activity was increased in aging kidneys.  The number of apoptotic cells increased in kidney with advancing age(P＜005). The p21WAF1/CIP1/SDI1 staining appeared in the podocyte and interstitium in kidney. The staining intensity of p21WAF1/CIP1/SDI1 in kidneys in old animals was markedly increased, as compared to that in young and middleaged rats (P＜005).The mRNA level of p21WAF1/CIP1/SDI1 was significantly increased in aging kidneys, as compared to that at the age of 3 and 12 months, meanwhile the p21WAF1/CIP1/SDI1 proteins expression was dramatically increased with advancing age (P＜005). Ｃｏｎｃｌｕｓｉｏｎｓp21WAF1/CIP1/SDI1 expression increases with the aging of kidneys, which may serve as an important marker of organismal aging.

Key words: p21WAF1/CIP1/SDI1, kidney, aging, rat