Alcohol-induced testicular atrophy in the adult male rat.

Abstract

The effect of ethanol feeding on testicular function and structure in adult male rats was studied in alcohol-fed animals, isocalorically fed controls, and weight-starved controls. Testicular weight was reduced by more than 50% in alcohol-fed animals compared to the control groups. Marked disruption of the histological appearance of the testes was observed in the alcohol-fed animals when compared to the controls. Specifically, there was prominent reduction in the mean seminiferous tubule diameter (P < 0.01) and number of contained germ cells (P < 0.01). Plasma levels of testosterone (P < 0.01) were reduced in the alcohol-fed animals when compared to either of the two control groups. In contrast, plasma estradiol levels were reduced in the alcohol-fed and weight-starved animals when compared to those of the isocaloric controls {P < 0.05). Plasma FSH levels in the alcohol-fed animals were twice those of the controls (P < 0.01), while no difference in plasma LH levels was observed among the various groups. Acu te alcohol infusion in castrate rats produced a significant reduction (P < 0.05) in plasma LH and reduced the responses of both FSH and LH to LRF stimulation (P < 0.05). LRF stimulation of castrate alcohol-fed rats was followed by an even greater reduction in the LH response (P < 0.01). These results establish that: 1) ingestion of a diet containing 5% ethanol can produce gonadal atrophy and reduce plasma testosterone and estradiol levels in adult male rats; 2) such gonadal injury occurs despite the absence of important biochemical or structural liver disease and can not be ascribed to caloric deprivation associated with chronic ethanol ingestion; 3) ethanol infusion of castrate rats acutely reduces basal LH secretion and blunts the response of such rats to LRF; and 4) LRF responses of castrate rats chronically fed alcohol are markedly reduced when compared to those of either castrate isocaloric or weightstarved controls