Androgen-sensitive period of humoral immune reactivity development in male mice

The influence of androgens on the humoral immune reactivity development was investigated in male CBA mice. Positive correlation was found to exist between the plasma androgen level and the primary immune response throughout the pubertal period. The androgen-sensitive period of the humoral immune reactivity development coincided with the early stages of sexual maturation (from the 18th to the 30th day of life). In mice orchidectomized on the 18th day of life (18 ORx) the immune response followed the pattern of that in intact males up to 3 months of age but did not reach its peak at 4 months of age. On the contrary, in mice orchidectomized on the 30th day of life (30 ORx) the immune response was maximal at 2 months of age and remained high thereafter. Ten-day treatment of 18 ORx mice with daily injections of testosterone propionate at a dose of 0.1 or 1 mg/kg b.w. was ineffective in making their immune reactivity pattern similar to that in 30 ORx mice, while daily injections of 5 alpha-dihydrotestosterone (DHT, 1 mg/kg b.w.) was effective. The results suggest that the stimulating influence of testes on the humoral immune reactivity development in maturing mice is effected via DHT.