Initiation of Spermatogenesis May Require Simultaneous Action of Two Steroid Hormones: Estradiol and Testosterone

摘要

Prepubertal male rats were daily injected between the 5tb and the 15th day of life with testosterone propionate (TP) or estradiol benzoate (EB) or TP+EB. On the 16th day of life blood was taken for determinations of testosterone (T), estradiol (E), and rat-FSH and rat-LH. Testes were processed for histology and quantitative analysis of seminiferous epithelium was performed. None of the treatments changed serum levels of FSH and LH. EB significantly decreased blood T, testis weight and Sertoli cell number. Number of A spermatogonia increased but further steps of spermatogenesis were inhibited. After TP testicular weight and numbers of cells were not affected, while TP+EB increased prominently testicular weight and Sertoli cells number and spermatogenesis was accelerated. It appears mat in the presence of FSH, initiation of testis maturation require simultaneous action of T and E, but neither one of the hormones separately.