Effect of local heating of rat testes after suppression of spermatogenesis by pretreatment with a GnRH agonist and an anti-androgen.

The effects of local heating of rat testes, in which spermatogenesis had been suppressed with injections of a GnRH agonist and an anti-androgen, were examined. Although the detrimental effects of heating were not as marked as those found in the testes of non-injected rats, the testes in which spermatogenesis was suppressed also showed a significant reduction in mass, the number of spermatozoa, tubular diameter and the percentage of normal tubular cross-sections at day 35 after heating. The results indicate that heating has an effect on cells in the testis other than those shown to be most susceptible to heat, namely pachytene spermatocytes and early spermatids, which were absent or markedly reduced in number when spermatogenesis was suppressed. The long-term effects of heating on the above parameters, as reported in a previous study, were also confirmed. However, in testes in which spermatogenesis was suppressed at the time of heating, there appeared to be no or a reduced long-term impairment of spermatogenesis, as determined by testis mass, the percentage of qualitatively normal tubules and epididymal sperm counts.