A. Gerard et al., GROWTH-RESPONSE OF ADULT GERM-CELLS TO RAT ANDROGEN-BINDING PROTEIN AND HUMAN SEX HORMONE-BINDING GLOBULIN, Hormone research, 45(3-5), 1996, pp. 218-221
Androgen-binding protein (ABP) is produced by Sertoli cells depending
on the development and the stage of the spermatogenic cycle. Germ cell
proliferation is at its peak when ABP is at its peak and secreted tow
ards the testicular basal compartment containing spermatogonia and pre
meiotic spermatocytes. Rat isolated adult germ cell DNA synthesis was
studied in vitro in the presence of ABP with and without steroids and
in the presence of pure or recombinant sex steroid hormone-binding glo
bulin (SHBG) using thymidine incorporation. Results are: SHBG is able
to promote DNA synthesis in the absence of cofactors. Testosterone rea
cted negatively to the stimulatory effect of SHBG. We conclude that AB
P, the physiological steroid-binding protein, should be considered as
a paracrine regulator of spermatogenic DNA synthesis in the adult rat.