Assessment of Ante- and Postnatal Development of the Offspring of Male Rats Crossed in Delayed Periods after Treatment with Methotrexate in Low Doses.

We studied ante- and postnatal development of the offspring of intact female rats crossed with males injected with low doses of methotrexate 3 and 6 months before mating. The time of crossing corresponded to the manifestation of the cytostatic effect on spermatogonial stem cells. The offspring of methotrexate-treated males was characterized by increased preimplantation losses and fetal growth restriction in the antenatal period and inhibition of physical development, delayed formation of sensory-motor reflexes, and impaired learning abilities in the postnatal period.

Delayed Consequences of the Toxic Effect of Paclitaxel on the Testes of Prepubertal Rats and Their Correction with p-Tyrosol.

Delayed gonadotoxic effects were revealed in outbred male sexually mature rats (SD) after exposure to paclitaxel in the prepubertal period, and the possibility of their correction with p-tyrosol was shown. It was found, that administration of paclitaxel does not inhibit the ability of animals to conceive, but impairs the reserve capacity of the testicular tissue. In intact female rats crossed with male rats receiving paclitaxel, increased post-implantation fetal death was observed. Combined administration of paclitaxel and p-tyrosol alleviated the delayed effects of the cytostatic treatment on the prepubertal testis.

Experimental Evaluation of Long-Term Toxic Effects of Methotrexate on Male Reproductive System.

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.