Efficacy of estrogen in preventing chronic renal allograft rejection in rats

Abstract

Objective Standard rat model of chronic renal allograft rejection was used to evaluated the effect of estrogen on chronic renal rejection. Methods Kidney transplantation was performed with male/female Fisher rats as donors and female Lewis rats as recipients. The recipients in the experimental groups were treated with estrogen, 25!μg/kg every another day, by means of subcutaneous injection. After 16 weeks of treatment, renal function and the histological disorders of chronic rejection were studied. The infiltration of CD5+ and CD68+ cells and the expression of ICAM-1 and TGF-β1 mRNA in the allografts were evaluated by using immunohistological staining and reverse transcription polymerase chain reaction respectively. Results Compared with control group, the 24-h urine protein in the experimental groups was markedly decreased (52.9±19.0!vs 580.1±226.3!mg/24!h, P<0.01), serum creatitine level lowered (1.05±0.02!vs 2.05±0.31!mg/24!h, P<0.01) and the creatitine clearance increased (0.32±0.02!vs 0.13±0.05!ml*min-1*100g-1, P<0.01). The infiltration of CD5 and CD68 positive cells, interstitial fibrosis, glomerular sclerosis and vascular intimal thickening in the allografts were alleviated in the experimental groups, in consistence with decreased expression of ICAM-1 and TGF-β1 mRNA. Conclusions Estrogen can prevent chronic renal rejection and the influenced expression of above cytokins might be involved in the mechanisms. These results suggest that estrogen may be a drug potentially against chronic renal rejection.