[The reproductive function of male rats following space flight on the Cosmos-1667 biosatellite]

After the 7-day space flight of Cosmos-1667 the reproductive system of white rats was investigated. No differences between the flight rats and synchronous and vivarium controls were detected with respect to such parameters as the testis and epididymis weight, testicular content of spermatogonia, spermatocytes, spermatids, spermatozoa, Leydig's cells and Sertoli's cells, and the number of normal and atypical spermatozoa in the epididymis. Nuclei of Sertoli's cells were similar in size in the flight and control rats. Electron microscopy of the first order spermatocytes showed no increase in the frequency of chromosome aberrations. Postflight, the flown males were mated with control females; their sex activity and their offspring were normal; the pups did not differ from the norm with respect to the litter size, proportion of males and females in the litter, growth rate in the postnatal period, physical development or function of the nervous system. These observations allow the conclusion that short-term space flight produces no effect on the reproductive system of white rats.