Macrophage may responses to androgen via its receptor.

Background: Sex hormones have profound effects on immune responses and may influence the disease which caused by intracellular parasite(Leishmania) and bacterial (tuberculosis)and also autoimmune disease such as rheumatoid arthritis (RA). It has also been demonstrated that 5alpha-Dihydrotestosterone (5alpha-DHT) modulate nitric oxide and cytokine release by macrophages. These effects seem to be exerted by specific receptors for androgen in macrophages.

Material/methods: Protein secretion: The effect of 5alpha-DHT on protein secretion by peritoneal macrophages of NZB\BALBc mice was investigated using radiolabelled protein secretion following SDS-PAGE and Fluorography. Binding assay: Androgen binding was also investigated using an autoradiography method. Peritoneal macrophages were treated with [3H]- 5alpha-DHT and incubated for 2 h before smearing on to microscope slides. Slides were air dried, dipped in Kodak NTB photographic emulsion, sealed in light proof boxes and left at 4 degrees C for 6 weeks.

Results: The results showed that protein secretion by macrophages changed under 5alpha-DHT treatment. Analysis of the data according to quantitation of [(3)H]-5alphaDHT binding receptors in fixed-slide mounted cells, identified a high specific androgen binding at physiological concentration. The receptors had a relatively high affinity for the 5alpha-DHT, So that binding affinity was not inhibited in the presence of 100-fold excess of non labelled 17-beta Estradiol.

Conclusions: These results suggest that the immunosuppressive action exerted by androgen is at least partially achieved through a direct influence on macrophages.