The Association between Granulosa Cell Aromatase Activity and Oocyte-Corona-Cumulus-Complex Maturity from Individual Human Follicles*

Abstract

The steroidogenic capability of granulosa cells isolated from 12 preovulatory human follicles was correlated with the stage of maturation of the corresponding oocyte-corona-cumulus-complex ( OCCC ). Individual follicles from human menopausal gonadotropin (hMG) stimulated cycles were aspirated 36 h after administration of hCG. Granulosa cells were cultured for 150 min and corresponding OCCC were evaluated for maturity before fertilization with human sperm. Granulosa cell aromatase activity was measured using 1 beta-3H-testosterone as substrate by quantitating the amount of 3H2O produced. Progesterone production by the granulosa cells was measured as was follicular fluid levels of combined hCG and LH activity and FSH and PRL. Follicular fluid concentrations of combined hCG plus LH activity decreased somewhat while FSH levels increased as OCCC matured. PRL levels did not vary. Granulosa cell progesterone production did not change with maturity of OCCC . However, aromatase activity decreased as OCCC matured with levels from granulosa cells with immature OCCC vs. intermediate and mature OCCC of 260 +/- 148 vs. 129 +/- 53 (SE) pg E2/10(5) cells, respectively (P less than 0.07). Although granulosa cells responded variably to hMG stimulation from individual to individual, and the response was not predictable from peripheral serum estradiol levels, follicles isolated from the same patient had a definite diminution in aromatase activity with OCCC maturation. From these preliminary results, aromatase activity in immediately preovulatory granulosa cells declined as OCCC matured in hMG/hCG stimulated cycles.

Effects of androgen on 17.BETA.-estradiol production by cultured human granulosa cells.

“…Therefore, it was confirmed that granulosa cells possess sufficient aromatase activity while shifting to a P-dominant situation at the ovulatory period. Also, in the human hMG-hCG cycle, it has been confirmed that granulosa cells sampled just after hCG injection have high aromatase activity (Dlugi et al 1984 ;Polan et al 1984).…”

Paxillin knockout in mouse granulosa cells increases fecundity

“…Many factors that determine female fertility have yet to be examined in relation to paxillin. GC communications to oocytes can translate into oocyte quality: for example, aromatase activity in cumulus GCs has been linked to oocyte maturation in preovulatory follicles [71]. We have not yet investigated whether paxillin loss in GCs affects oocyte quality.…”

Equine ovarian aromatase: evidence for a species specificity

“…The human placental aromatase is located in the smooth endoplasmic reticulum and belongs t o the superfamily of monooxygenases. Aromatase has been found in reproductive gonads (Polan et al 1984;Rommerts et al 1982), placenta (Inkster and Brodie 1989), human skin fibroblasts, brain, and adipose tissue (Stillman et al 1990;Hutchison et al 1990;Lueprasitsakul and Longcope 1991). It has been suggested (Osawa and Igashiyawa 1984) that different aromatase enzymes might occur in different tissues since several estrogens are produced, namely estradiol-17P in ovary, estriol in placenta, and estrone in adipose tissue.…”