Endocrine Abstracts

Anti-Mullerian hormone (AMH), a member of transforming growth factor β (TGF-β), shows different sex-related functions. In male, from the fetal development till the puberty, the expression of AMH by Sertoli cells causes regression of Mullerian ducts with subsequent testicular differentiation. Mainly studied in female, AMH produced by ovarian granulosa cells inhibits both initiation of primordial follicle growth and the FSH-stimulated follicle growth. Moreover, recent studies have shown a negative relationship between the CYP19 mRNA expression, the key enzyme converting androgen to estrogen, and the concentration of AMH retrieved in fluid from small human antral follicles. To our knowledge no data have been produced to clarify the role of AMH on the regulation of expression of the steroidogenic aromatase cholesterol side-chain cleavage (P450scc) which catalyzes conversion of cholesterol to pregnenolone.

In this study, we analyzed the effect of increasing concentrations of rhAMH (range 1–100 ng/ml) at different time point either on CYP19 or P450ssc aromatases expression in primary culture of human granulosa-lutein cells (hGC) recovered from patients who underwent the IVF protocol.

Furthermore, rhAMH (10 ng/ml) was added to colture medium of hGC previously treated for 24 h with rLH (50 ng/ml), rFSH (50 ng/ml) alone or combined. The CYP19 and P450scc mRNA expression, normalized by housekeeping gene RpS7, was evaluated by RT-qPCR. Negative controls using corresponding amount of vehicle control for each hormone treatment were performed. Our results show that the strong induction of CYP19 and P450scc mRNA generated by gonadotropins treatment (alone and combined) was reverted by rhAMH although rhAMH alone did not affect aromatases basal expression in any of the concentrations tested.

Results offer new insights to clarify the relationship between hormones leading the early phases of folliculogenesis suggesting that AMH could play a pivotal inhibitory role on both CYP19 and P450scc gene expression in hGC gonadotropin stimulated.