title: Differential effects of epidermal growth factor on the differentiation of type A spermatogonia in adult mouse cryptorchid testes in vitro.
abstract: The effect of epidermal growth factor (EGF) on testicular germ cell differentiation was investigated. Testicular fragments from surgically prepared cryptorchid testes of adult mice were cultured for 9 days in serum-free media containing various concentrations of EGF. Histological sections of testis were examined under a light microscope and each type of germ cell and mitotic cell in the seminiferous tubules was counted per 1000 Sertoli cells. EGF at concentrations ranging from 100 to 200 ng/ml induced differentiation of type A spermatogonia. The observed maximal stimulatory activity of EGF at a concentration of 100 ng/ml was 30% of the positive control cultures treated with calf serum. EGF at concentrations ranging from 1 to 100 ng/ml significantly inhibited the mitotic activity of FSH, FSH plus retinol, or FSH plus fetuin on type A spermatogonia and their differentiation. The number of type A spermatogonia in testes cultured with FSH, FSH plus retinol, or FSH plus fetuin decreased when EGF was added. On the other hand, EGF stimulated the differentiation of type A spermatogonia induced with fetuin but did not influence retinol-induced differentiation. It is proposed that EGF inhibits testicular germ cell differentiation by blocking the proliferation of type A spermatogonia stimulated by FSH.
authors.affiliation: Population Council, Center for Biomedical Research, New York 10021.
authors.forename: T
authors.initials: T
authors.lastname: Haneji
authors.forename: S S
authors.initials: SS
authors.lastname: Koide
authors.forename: Y
authors.initials: Y
authors.lastname: Tajima
authors.forename: Y
authors.initials: Y
authors.lastname: Nishimune
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D003456:Cryptorchidism / Q000473:pathology*; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006131:Growth Inhibitors / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008938:Mitosis / Q000187:drug effects; D013093:Spermatogonia / Q000187:drug effects* / Q000473:pathology; D014801:Vitamin A / Q000494:pharmacology; D000509:alpha-Fetoproteins / Q000494:pharmacology
chemical_list: D006131:Growth Inhibitors; D000509:alpha-Fetoproteins; D014801:Vitamin A; D004815:Epidermal Growth Factor; D005640:Follicle Stimulating Hormone