Effect of testosterone and estrogen supplementation on the resistance to systemic infection in mice.

species are the 4 leading cause of nosocomial infections in the US affecting both men and women. Since males of many species can be more susceptible to infections than females, we investigated whether male mice were more susceptible to systemic () infection and if sex hormones were responsible for sex-dependent susceptibility to this infection. Non-gonadectomized or gonadectomized mice were supplemented with sustained release 5α-dihydrotestosterone (5αDHT) or 17-β-estradiol (E2) using subcutaneous pellet implantation. Mice were challenged intravenously with 5 × 10 /mouse seven days after pellet implantation and monitored for survival and weight change. We observed that male mice were more susceptible to systemic infection than female mice while gonadectomized male mice were as resistant to the infection as female mice. 5αDHT supplementation of gonadectomized female or male mice increased their susceptibility to the yeast infection while E2 supplementation of gonadectomized male mice did not increase their resistance to the infection. Overall, our results strongly suggest that testosterone plays an important role in decreasing resistance to systemic infection.