Comparative effects of niridazole on spermatogenesis and reproductive capacity in the mouse, rat and Japanese quail.

Niridazole is an effective schistosomicidal compound which, at lower dose levels, affects schistosome gonads. Its antifertility and possible mutagenic effects after various courses of oral treatment were compared in mice, rats and Japanese quail (Coturnix coturnix japonica). In all three species the meiotic stage of spermatogenesis was particularly affected. In mice the highest dose rate (five daily doses of 100 mg/kg) produced sterility during the 4th week. Rats were more susceptible, the compound producing prolonged and, in some animals, permanent sterility against which HCG treatment offered no protection. In quail only a brief phase of sterility occurred. Niridazole appears to be non-mutagenic since dominant lethal mutations were not produced in dose-response studies. Minimal changes in testis histology occurred in the mouse, but in rats severe damage persisted even in animals which had recovered their fertility.