Testicular and epididymal aldehyde dehydrogenase in rodents: modulation by ethanol and disulfiram

The distribution of (newly found) NAD-dependent aldehyde dehydrogenase (ALDH) was determined in the rat testis and epididymis as a function of age. There were changes in specific activity of testicular ALDH as a function of age. Epididymal ALDH, which is found evenly distributed between the caput and cauda epididymis, increased initially from the 20th day after birth to th 50th day and remained little altered thereafter in both the caudet and the caput portion of the epididymis. Testicular and epididymal ALDH were found species-dependent with the hamster testis and the rat epididymis showing greater specific activities from the rest of the species studied, respectively. Determinations of testicular ALDH in various mouse strains indicate that it is strain-dependent. Intake of 25% (v/v) ethanol solution as the sole drinking fluid for 10 consecutive days inhibited testicular ALDH in the three mouse strains studied. Administration of disulfiram, 15 mg/kg/day for 60 consecutive days, exerted inhibitory action on testicular and epididymal ALDH in the rat. Intraperitoneal injection of pyrazol, 100 mg/kg once daily for 7 days, resulted in inhibition of epididymal but not of testicular ALDH. It is suggested that testicular and epididymal ALDH may play a role in the toxic action of ethanol-derived acetaldehyde on the gonad.