The morphological and functional state of the reproductive system was studied in male outbred rats (SD stock) and male F1(CBA×C57BL/6) mice after long-term (3 months) methotrexate administration. The drug was administered subcutaneously once a week for 4 weeks, the dose for male rats was 1 mg/kg, for male mice 2.2 mg/kg. It was found that male rats retained the ability to conceive, their reproductive potential was not limited by increased risk of embryo death. At the same time, signs of astheno- and pathospermia were revealed. The testicular tissue was characterized by reduced content of the sources of the proliferative pool of spermatogenesis. In mice treated with methotrexate, increased content of DNA breaks was detected in the testicular cells.
Keywords: delayed toxic effects; methotrexate; mice; rats; spermatogenesis.