light and electron microscope study of the effect of sildenafil citrate on the kidney of cyclosporine-treated albino rats

ABSTRACT

The goal of the current study was to clarify the effects of the phosephodiesterse-5 inhibitor, sildenafil citrate [SC], on the kidney of cyclosporine A [CsA]-treated albino rats. Thirty adult male albino rats [200-250 gm] were used in the present investigation. They were allocated into three equal groups control CsA- treated and both CsA and SC- treated. The animals were sacrificed after three weeks and blood samples were withdrawn by direct cardiac puncture to determine the levels of urea and creatinine in plasma. Also, small slices of the kidney were processed for histological histochemical and immunohistochemical study. The CsA-treated rats showed a significant increase in both blood urea nitrogen and plasma creatinine. Then, followed a significant decrease in their values in the CsA and SC- treated animals. Histological examination of the kidney of the CsA- treated group exhibited a degeneration in both the tubular epithelium and the glomerulus with a relative widening of the sub-capsular spaces. Areas of interstitial haemorrhage and cellular infiltration were encountered. There was a relative increase in the amount of interstitial fibrosis. Ultrastructurally, the minor foot processes of the podocytes were enlarged and fused around an apparently thickened basement membrane with an apparent reduction in the number of filtration slits. The cells of proximal convoluted tubules showed a marked reduction in their basal infoldings. The nucleus became irregular in outline and the cytoplasm housed degenerated mitochondria. Succinic dehydrogenase reaction got weak while the acid phosphatase one became strong. A moderate to strong immune reaction to caspase- 3 was detected in the renal tubules. On the other hand, albino rats receiving both CsA and SC showed an improvement in the histological architecture and in both the histochemical and immunohistochemical reactions. In conclusion, the present findings lend support to a lessening role of the phosphodiesterase-5 inhibitor, SC, on the CsA- induced renal effects