Interaction between activin A and @entity268 in the induction of FSH receptor in cultured XXXX granulosa cells.

@entity268 @entity1928 @entity35 @entity7410
The acquisition of FSH receptor during preantral folliculogenesis is believed to be a key step in the subsequent development of follicles. We examined the interaction between activin and @entity268 in FSH receptor induction in @entity35 granulosa cells by measuring 125I-FSH binding and FSH receptor mRNA. In the 125I-FSH binding study, 0.2 mM @entity7410 and 1 microM @entity1928 were maximally effective in FSH receptor induction (169 and 220% respectively of control), while higher concentrations gave attenuated responses. It appears that @entity268 has ambivalent effects on FSH receptor induction depending on the concentration and length of exposure. Activin alone dramatically increased the number of FSH receptors (314% of control). Moreover, synergistic effects of activin and @entity7410 or @entity1928 were observed on FSH receptor induction: a combination of activin (80 ng/ml) and low doses of @entity7410 (0.2 mM) or @entity1928 (1 microM) was most effective (160 or 140% of that induced by activin alone) and receptor levels reached a maximum at 24 h. These levels than markedly decreased after 72 h of incubation. Northern blot analysis revealed that the combination of activin (80 ng/ml) and @entity7410 (0.2 mM) or @entity1928 (1 microM) increased FSH receptor mRNA to about 140% of that induced by activin alone. These results indicate that activin and @entity268 induced FSH receptor synergistically. However, activin did not enhance the production of @entity268 induced by @entity1928 . In addition, a protein kinase A inhibitor (H89) (2 microM), which inhibited the effects of @entity1928 , had no effect on the action of activin.(ABSTRACT TRUNCATED AT 250 WORDS)
