Preparation of infertile male rabbits by local electron beam irradiation for intratesticular transplantation of autologous bone marrow stem cells

PURPOSE: To explore an efficient and safe protocol for the preparation of infertile male rabbits from which bone marrow stem cells (BMSCs) could be isolated and cultured. METHODS: Autologous BMSCs could be used for intratesticular transplantation and male infertility research. For this model, various doses (e.g., 6, 8, 10, or 12 Gy) of electron beam irradiation from a linear accelerator were locally applied to the scrotum of 5-month-old male New Zealand white rabbits. The effects of irradiation were compared between treatment groups, and with age-matched normal controls. Both morphology and hollow ratios of seminiferous tubules (HRST) were examined two, four, six, eight and 12-weeks post-irradiation. RESULTS: The seminiferous epithelium showed varying degrees of damage in all treatment groups compared with unirradiated controls, yet Sertoli and Leydig cells appeared unaffected. A dose-dependent response in spermatogenesis was also observed. BMSCs that were isolated and cultured from rabbits of the normal control group and the 12 Gy treatment group were compared with respect to morphology and growth. Starting at 6 weeks, HRST of the 12 Gy-treatment group were stable, and were the highest among all the groups. BMSCs from rabbits treated with 12 Gy also exhibited similar growth as the control group. CONCLUSION: Local dose of 12 Gy to the testes of 5-month-old male New Zealand rabbits is a protocol with which to obtain autologous bone marrow stem cells.