Aim: To study the effect of Ureaplasma urealyticum (UU) infection on germ cell apoptosis of male rats. Meth-ods: Male rats were infected artificially with UU serotype 8 (T_(960)). Morphological changes of germ cells in the sem-iniferous tubules and the lumen of the epididymides were observed under the light microscope. Fluorescence-conjugatedpolyclonal antibodies to Fas and Fas ligand (FasL) were used to localize Fas and FasL. TUNEL staining of germ cellsand Sertoli cells was performed by the AKPase method. TUNEL-positive rate (% positive cells) and TUNEL-positivearea (area occupied by stained cells) were analysed by KS400 Image Analysis System. The DNA laddering analysiswas performed by agarose gels electrophoresis. Results: In those rats infected with UU; (1) Exfoliated germ cellswere dramatically increased. Many multinucleated giant cells were found in the seminiferous tubules and the lumen ofthe epididymides. (2) The number of TUNEL-positive cells and the TUNEL-positive area were significantly increased.(3) The expression of Fas and FasL in germ cells and Sertoli cells was up-regulated. (4) Discrete bands of fragmentedDNA were found in the testicular cells. Conclusion: In male rats, germ cell apoptosis was increased in UU infec-tion . (Asian J Androl 2001 Sep; 3: 199 - 204)
