ABSTRACT
The present work investigated the changes induced by cyclosporine on the liver and kidney and clarified the possible protective role of calcium channel blockers. Cyclosporine caused distortion of the liver parenchyma as well as severe congestion in the central vein. Also there was loss of cellular demarcation with indistinct cell boundaries. By the electron microscope the hepatocytes in the affected areas revealed depleted cytoplasm, and mitochondria with partial loss of their cristae. The rough endoplasmic reticiulum showed slight dilatation and fragmentation. The calcium channel blocker [amlodipine] enhanced the preservation of the control pattern in most hepatocytes apart from few hepatocytes showing areas of depletion, irregular arrangement of endoplasmic reticiulum, few glycogen granules and smaller nuclei. Regarding the kidney, cyclosporine caused different modalities of degeneration in the capillary tuft of the renal corpuscles. Both the proximal and distal tubules showed widening of their lumen, distortion of their cellular pattern As for the cells of the proximal tubules, they showed disrupted brush border, loss of the basal striations with irregular nuclei. Some tubules also contained areas of exudation. Extravasation of red blood corpuscles was evident. The podocytes, by the electron microscope, had vacuolated cytoplasm and irregular nuclei. The mesangial cells had paler matrix than the control group. Peritubular fibrosis was observed. The cytoplasm of the cells of the proximal tubules contained large lysosomes and autophagic vacuoles