In vitro effect of sex steroids on cytotoxic activity of splenic macrophages in wall lizard (Hemidactylus flaviviridis).

Sexual dimorphism was observed in nitrite release and IL-1-like molecule production by splenic macrophages of the wall lizard (Hemidactylus flaviviridis), with a higher level in females than in males. Gonadectomy in both males and females resulted in a considerable increase of nitrite and IL-1-like molecule secretion, suggesting that the sex hormones inhibit cytotoxic activity of macrophages. To verify this assumption, dose- and time-related in vitro experiments with male and female sex steroids, dihydrotestosterone (DHT) and 17beta-estradiol (E(2)), respectively, were carried out. E(2) and DHT both significantly reduced the nitrite release and IL-1-like molecule production with an increase of dose or duration of treatment.