Abstract: 　AIM: investigate the effect of the male sex hormone, testosterone (Te),on apoptosis of bone marrow derived macrophages (BMMs) from female C57BL/6j mice METHODS: Propidium iodide (PI) staining and transmission electron microscopy (TEM) techniques were used to investigate apoptosis specific morphological changes. BMMs derived from Te treated mice and Oil treated mice were challenged with Leishmania donovani (L.d. ), Oligo nucleosomal DNA were extracted 24 h post infection to detect apoptosis. RESULTS: The removal of M CSF from the medium could induce BMM apoptofsis. And the DNA fragmentation assay also indicated that: ① there was no difference in the amount of apoptotic cells between Te and Oil group; ② Te+L.d. group had significantly less dead cells than Oil+L.d. group demonstrating that Te could prevent apoptosis of macrophage infected with L.d. to a greater extent. CONCLUSION: Te inhibits apoptosis of the macrophages infected with L.d ., however, this inhibition did not occur in the macrophages uninfected with L.d. Te induced macrophage apoptosis inhibition may play an important role in Te induced immunosuppression.

Key words: Apoptosis, BMMs, Leishmania donovani, testosterone