Reduced aromatase activity in granulosa cells of women with endometriosis undergoing assisted reproduction techniques

Abstract

The aim of the present study was to measure the in vitro aromatase activity in granulosa cells of women with endometriosis submitted to assisted reproduction techniques. A case–control study was conducted on eight patients with endometriosis and eight with other infertility causes submitted to in vitro fertilization or intracytoplasmic sperm injection. Granulosa cells were obtained from pre-ovulatory follicles during oocyte retrieval and cultured for 24 h in the presence or absence of testosterone (2×10⁻⁶ and 2×10⁻⁵ M), follicle-stimulating hormone (FSH) and insulin-like growth factor-I (IGF-I) (both at 50 ng/ml). Estradiol (radioimmunoassay) was measured in the obtained culture fluids. The basal production of estradiol and its production under testosterone addition to the culture (aromatase activity) were analyzed. Reduced aromatase activity was detected in cultured granulosa cells in endometriosis cases, compared with controls, when testosterone was added at the concentration at 2×10⁻⁶ M (p = 0.0303). The basal production of estradiol was also reduced in endometriosis patients (p = 0.0390). The effect of addition of FSH and IGF-I did not differ between groups. In conclusion, the in vitro basal production of estradiol and aromatase activity in granulosa cells were reduced in women with endometriosis submitted to assisted reproduction techniques, compared with the control group.

Keywords:

• Aromatase
• endometriosis
• granulosa cells
• assisted reproduction
• in vitro fertilization
• intracytoplasmic sperm injection