Establishment of a murine model of spermatogenesis recovery by two doses of Busulfan injection

Abstract

Objective To establish a model of spermatogenesis recovery in male Kunming mice.Methods Adult male Kunming mice were randomly treated with busulfan injeetion intraperitoneally at different doses or types(A:10 mg/kg;B:20 mg/kg;C:two doses of 10 mg/kg,24 days apart).Testes were dissected out 1 w,2 w,3 w,4 w,6 w and 8 w after treatment,and normal testes were used as control.The expression of Ki-67 in germ cells was detected by immunohistochemistry and apoptosis was assessed by TUNEL in two doses of busulfan treatment group.Results The damage effect in seminiferous epithelium by two doses of 10mg/kg busulfan injection was between single dose of 10 mg/kg and 20 mg/kg.In week 2,only fewer dispersed spermatogonia(As type)survived in close contact with the basal portions of adjacent Sertoli cells.In week 3,the number of As type of spermatogonia increased.In week 4,differentiated spermatogonia and spermatocytes appeared.In week 6-8,spermatogenesis regeneration took place and morphology of seminiferous epithelium got back tO normal gradually.The apoptotic indices(AI)of germ cells in 1 and 2 week groups were both higher than those in control group.Later,the AI began tO drop in sequence.In week 6-8,it got back to the level of control group.In week 1 and 2,the Ki-67 positive rate of spermatogonia was lower than that in control group.It rebounded rapidly tO apex in week 3,descended in week 4 and restored to the controllevel in week 6 and 8.Conclusions Two doses of busulfan treatment could establish a mice model of recovery of spermatogenesis and apoptosis was possibly an important mechanism of germ cells destroyed by busulfan. Key words: Busulfan; Ki-67 antigen; Spermatogenesis