The anti-Mullerian hormone (AMH) acts as a gatekeeper of ovarian steroidogenesis inhibiting the granulosa cell response to both FSH and LH

Anti Mullerian Hormone (AMH) has a negative and inhibitory role in many functions of human granulosa-lutein cells (hGCs) including notoriously the reduction of the aromatase CYP19A1 expression induced by follicle-stimulating hormone (FSH). No data have been provided on the possible role of AMH in modulating the response to luteinizing hormone (LH) (alone or combined with FSH) as well as its effect on other enzymes involved in steroidogenesis including aromatase P450scc. The aim of this study was to investigate the role of AMH as regulator of the basal and stimulated steroids production by hGCs. Primary culture of hGCs were incubated with hormones AMH, LH, and FSH, alone or in combination. The CYP19A1 and P450scc messenger RNA (mRNA) expression, normalized by housekeeping ribosomal protein S7 (RpS7) gene, was evaluated by reverse transcriptase quantitative PCR (RT-qPCR). Each reaction was repeated in triplicate. Negative controls using corresponding amount of vehicle control for each hormone treatment were performed. AMH did not modulate the basal mRNA expression of both aromatase genes at any of the concentrations tested. Meanwhile, the strong mRNA induction of CYP19A1 and P450scc generated by a 24-h gonadotropin treatment (alone and combined) was suppressed by 20 ng/ml AMH added to culture medium. These findings contribute in clarifying the relationship between hormones regulating the early phase of steroidogenesis confirming that AMH is playing a suppressive role on CYP19A1 expression stimulated by gonadotropin in hGCs. Furthermore, a similar inhibitory effect for AMH was observed on P450scc gene expression when activated by gonadotropin treatment.