Androgen Receptor in Macrophages of Male Rat is Greater Than in Female

The presence and possible sex differences of androgen receptor in peritoneal macrophages was investigated using immunomagnetic beads. Macrophages were incubated with different concentrations of [³H]-5αDHT in the presence or absence of a 100 fold excess of unlabelled 5α-DHT. Labelled cells were separated from unbound steroid by immunomagnetic beads coated with anti-rat macrophage antibody. The binding identified in the rat macrophages was highly selective towards androgenic compounds. The dissociation constant (kd) value for the receptor was calculated to be 3.3X10^-9M and 5X10^-9M for macrophages of male and female rat respectively. The number of receptors in each cell was 792±3 and 120±1 for male and female respectively. Indicating a sex differences in androgen receptor (p<0.001). Taken together it can be concluded that part of sex differences in immune responses and also auto-immune disease could be related to sex differences in androgen receptor in macrophages.