EFFECT OF NILVADIPINE ON ADRENOCORTICAL CELL-PROLIFERATION AND STEROIDOGENESIS IN EARLY-STAGE OF ADRENAL REGENERATION

The influence of nilvadipine, a novel calcium channel antagonist on ad renal regeneration was investigated in male Wistar rats. The estimatio n of the mitotic index after administration of colchicine was suppleme nted by an immunoperoxidase technique with monoclonal antibodies to br omodeoxyuridine. Plasma corticosterone was determined by a radioimmuno logical assay. Nilvadipine was given subcutaneously in two doses (0.2 and 1 mg/kg) to animals subjected to adrenal enucleation combined with contralateral adrenalectomy. It was found that nilvadipine inhibited the proliferation ratio of adrenocortical cells on the 4th day after s urgery in a dose-dependent manner. The inhibitory effect of nilvadipin e became less significant by 8 days after operation. However, no chang es in corticosterone secretion were observed.