The ultrastructural localization of NADPH-diaphorase enzymatic activity in the Leydig cells of mouse. effects of ethanol administration.

The effects of the chronic ethanol treatment on the NOS-related NADPH-diaphorase activity were described in the mouse Leydig cells by means of transmission electron microscope. The recovery of the Leydig cells was also examined during a period of four weeks. About 10% of the Leydig cells showed various degrees of morphological alterations, consisting in increased number of lipid droplets, rarefaction and vacuolization of the cytoplasmic matrix. Other groups of Leydig cells (about 10%) revealed evident signs of degeneration. The NADPH-d activity was reduced both in apparently normal and injured Leydig cells and a moderate enzymatic reaction was only detected in the smooth endoplasmic reticulum. A week after the treatment an increased number of the degenerating Leydig cells and a further reduction of the enzymatic reaction were observed. Then, the Leydig cells showed a progressive recovery and four weeks after the treatment they exhibited a normal morphology and NADPH-d enzymatic reaction. These results demonstrated for the first time the inhibition of NOS activity in the Leydig cells after chronic ethanol administration.