Antiandrogenic Effects of Spironolactone: Hormonal and Ultrastructural Studies in Dogs and Men

Abstract
A decrease in the level of plasma testosterone and an increase in the level of plasma progesterone were noted after spironolactone had been administered for 20 days in 5 patients with prostatic carcinoma, as well as in 8 male dogs. Electron microscopic observation disclosed myelinlike bodies in the cytoplasm of Leydig and adrenocortical cells in dogs, contributing to a resolution of the mode of antiandrogenic action of spironolactone.