Restraint stress exacerbates alcohol-induced reproductive toxicity in male rats

Cumulative exposure to multiple stresses may lead to aggravating the toxicity of each stress, qualitatively or quantitatively altering biological responses because of toxicological interaction. In this study, we intended to determine the possible effects of restraint stress on reproductive toxicity due to ethanol usage in male rats. Early pubertal male Wistar rats were subjected to either restraint stress (5 h/day) or alcohol intoxication (2 mg/kg body weight) or both for 60 days. Body weights of control and experimental rats were similar during the 60 days of this study. Testes were harvested, weighed, and prepared for enzyme assays, and cauda epididymides were isolated for the determination of density, motility, and viability of stored spermatozoa. Restraint stress or alcohol treatment significantly reduced testis weight and caused significant reductions in steroidogenesis and spermatogenesis. Mean density, motility, and viability of stored spermatozoa were reduced in experimental rats. Plasma testosterone concentrations in rats subjected to restraint stress or alcohol were decreased compared with those of controls, concomitant with increased concentrations of LH and FSH in experimental rats. These data suggest that sub-chronic exposure to restraint stress or alcohol contribute to reduce testicular and epididymal function in exposed rats. The study also suggests that restraint stress exacerbates alcohol-induced reproductive toxicity in rats.