Germ cell apoptosis induced by Ureaplasma urealyticum infection

Aim. To study the effect of Ureaplasma urealyticum (UU) infection on germ c ell apoptosis of male rats. Methods: Male rats were infected artificially w ith UU serotype 8 (T-960) - Morphological changes of germ. cells in the sem iniferous tubules and the lumen of the epididyni-ides were observed under t he light microscope. Fluorescence-conjugated polyclonal antibodies to Fas a nd Fas ligand (FasL) were used to localize Fas and FasL. TUNEL staining of germ cells and Sertoli cells was performed by the AKPase method. TUNEL-posi tive rate ( % positive cells) and TUNEL-positive area (area occupied by sta ined cells) were analysed by KS400 Image Analysis System. The DNA laddering analysis was performed by agarose gels electrophoresis. Results: In those rats infected with UU: (1) Exfoliated germ cells were dramatically increase d. Many multinucleated giant cells were found in the seminiferous tubules a nd the lumen of the epididymides. (2) The number of TUNEL-positive cells an d the TUNEL-positive area were significantly increased. (3) The expression of Fas and FasL in germ cells and Sertoli cells was up-regulated. (4) Discr ete bands of fragmented DNA were found in the testicular cells. Conclusion: In male rats, germ cell apoptosis was increased in UU infection.