earticle

영어

The spermatogonial stem cell (SSC) transplantation technique has been utilized for the production of donor-derived sperms in the recipient animals. Depletion of the endogenous germ cells in the seminiferous tubules is the key technique for successful SSCs transplantation because it provides a place for transplanted donor germ cells settle in the seminiferous tubules. We previously reported that intra-testicular injection of 70% glycerin partially removed endogenous germ cells, but the effect varied among stallions. The main objective of this study was to find out an optimal dose and injection method by which endogenous germ cells of stallions are successfully depleted without disturbing functions of sperm production and libido. Each group of stallions (n=3) were treated with 1) 15 mg of busulfan/kg of BW, all at once (group 1), 2) 15 mg of busulfan/kg of BW, at 5 different times (group 2), or 3) none (control, group 3). The percentages of survival rate in group 1, 2, and 3 were 33 (1/3), 100 (3/3), and 100% (3/3), respectively. The percentage of Sertoli cell only cross section of seminiferous tubules were significantly higher (p<0.05) in group 2 (78.2±7%) compared to group 3 (0%). The averages of testicular weight (g) between group 2 (143.5±8.5 g) and 3 (179±1.0 g) were not significantly different (p<0.05). In group 2, the number of sperm production and motility (total and progressive) decreased after busulfan treatment. However, libido of stallions was not altered after treatment. In conclusion, weekly split IV injection of busulfan can be utilized to deplete endogenous germ cells for the purpose of preparing recipient stallions for spermatogonial stem cell transplantation.