Endocrinology. 1993 Mar;132(3):975-82.  

Activin is produced by rat Sertoli cells in vitro and can act as an autocrine
regulator of Sertoli cell function.

de Winter JP, Vanderstichele HM, Timmerman MA, Blok LJ, Themmen AP, de Jong FH.

Department of Endocrinology and Reproduction, Medical Faculty, Eramus
University, Rotterdam, The Netherlands.

The production of activin by Sertoli cells isolated from 21-day-old rats was
studied using the mesoderm-inducing activity of activin on Xenopus laevis animal
cap explants, immunoprecipitation and Western blotting. Furthermore, the effects
of recombinant bovine activin-A on rat Sertoli cell aromatase activity and FSH
and androgen receptor gene expression were examined. Animal cap explants from
Xenopus laevis blastulas elongated after culture in conditioned medium of
Sertoli cells cultured with or without ovine FSH or conditioned medium of the
mouse Sertoli cell-derived TM4 cell line. Animal cap explants cultured in
control medium remained spherical. This elongation was also found in the more
than 10-kilodalton fraction of the conditioned medium and after heating for 10
min at 95 C, indicating that heat-stable activin-like bioactivity is present in
the culture medium. Immunoprecipitation of [35S]methionine-labeled proteins and
Western blotting of Sertoli cell-conditioned medium with polyclonal antisera
against the inhibition beta-subunits indicated the presence of 24- to
25-kilodalton activin-like immunoreactive material. Sertoli cell aromatase
activity was dose-dependently stimulated by ovine FSH after 72 h of culture.
Recombinant bovine activin-A partly inhibited this stimulation in a
dose-dependent way. This inhibition was also found after 24 h of culture.
Furthermore, basal and FSH-stimulated androgen receptor mRNA expression in
Sertoli cells and binding of the synthetic androgen R1881 to Sertoli cells were
decreased after 24 h of culture in the presence of recombinant bovine activin-A.
In the same experiments, FSH receptor mRNA expression was not significantly
affected. These results indicate that activin can act as an autocrine regulator
of Sertoli cell function.

PMID: 7679985 [PubMed - indexed for MEDLINE]