Estradiol, progesterone, testosterone profiles in human follicular fluid and cultured granulosa cells from luteinized pre-ovulatory follicles.

BACKGROUND: The production of sex steroids by follicular cells is proposed to be influenced by the maturity of the incumbent oocyte. Thus steroid levels may reflect suitability of an oocyte for IVF. We examined follicular fluids and granulosa cell production of steroid from IVF patients in order to test the relationship between steroid levels and fertilization. METHODS: Follicular fluid and granulosa cells were extracted from 206 follicles of 35 women undergoing controlled ovarian stimulation. Follicular fluid was assayed for estradiol, progesterone and testosterone. Granulosa cells were cultured from individual follicles and their culture media assayed for production of these hormones after 24 hrs in vitro. Levels of steroids were correlated with follicular diameter, oocyte recovery and subsequent fertilization. RESULTS: Follicular fluid levels of progesterone were 6100 times higher than that of estradiol, and 16,900 times higher that of testosterone. Despite the size of follicle triggered after controlled luteinization, the levels of progesterone and testosterone were maintained at relatively constant levels (median 98.1 micromoles/L for progesterone, and 5.8 nanomoles/L for testosterone). However, estradiol levels were slightly lower in the larger follicles (follicular diameter 10-15 mm, median 25.3 nanomoles/L; follicles > = 15 mm, median 15.1 nanomoles/L; linear correlation r = -0.47, p < 0.0001). With respect to oocyte recovery, no steroid showed a significant association in follicular fluid levels. Similarly no difference in follicular fluid steroid levels was found for those oocytes that did or did not fertilize. Significant quantities of progesterone were produced by the granulosa cells but production was constant regardless of the size of follicle from which the cells originated. Estradiol levels were only detectable in 10 of 121 cultures examined, and testosterone in none. Interestingly, when an oocyte was present follicular estradiol levels correlated with progesterone levels. However, when absent, follicular estradiol levels correlated with testosterone levels but not with progesterone. CONCLUSIONS: The principle steroid product of luteinized pre-ovulatory granulosa is progesterone, a differentiation triggered by the gonadotropin surge. However, absolute steroid levels are associated with follicular size, not oocyte maturation/ability to fertilize.

High follicular fluid adenosine levels may be pivotal in the metabolism and recycling of adenosine nucleotides in the human follicle.

This study investigated the biochemical relationship between human follicular/oocyte maturity and the levels of follicular fluid purines. Intrafollicular levels of purine metabolites and creatinine are associated with oocyte presence, and the presence of such high levels of adenosine indicates a privileged site with no adenosine deaminase activity. Subgrouping according to oocyte recovery and fertilization revealed differences in correlation between the purine metabolites: Only where an oocyte was recovered and subsequently fertilized did follicular fluid adenosine, adenine, and hypoxanthine levels correlate with each other. Significantly, purines' correlation with levels of the terminal degradation product, uric acid, could only be seen in failed fertilization samples. Given the established metabolic pathways for adenosine triphosphate/adenosine diphosphate/adenosine monophosphate degradation, the results indicate maximization of 2 purine salvage pathways (from adenine and hypoxanthine) that pivot on the presence of high adenosine levels. Such optimized recovery may be necessary to build a store of salvaged adenosine phosphate for oocyte survival.

Human granulosa-lutein cell in vitro production of progesterone, inhibin A, inhibin B, and activin A are dependent on follicular size and not the presence of the oocyte.

OBJECTIVE: To investigate inhibin A, inhibin B, activin A, and P production by cultured granulosa cells (GCs) and what relationship this hormone production has to fertility. DESIGN: Luteinized GCs from individual follicles were cultured, and inhibin A, inhibin B, activin A, and P production were measured by ELISA at 24 and 72 hours. SETTING: Research laboratory and university hospital. PATIENT(S): Fifteen women who undertook an IVF-ICSI program, yielding 58 follicles. INTERVENTION(S): Individual follicular aspiration and preparation of GCs for culture. MAIN OUTCOME MEASURE(S): Inhibin A, inhibin B, activin A, and P production; oocyte retrieval; and fertility outcome. RESULT(S): Inhibin A, inhibin B, and P continued to be secreted by GCs in vitro, and activin A levels were detected only marginally in 56% of cultures. The rate of production also was dependent on the size of follicle from which the GCs originated but not on oocyte presence or ability to fertilize. Granulosa cell stimulation with hCG had no effect on inhibin A but increased P and decreased inhibin B production. CONCLUSION(S): A marked effect of luteal differentiation appears to be the inhibition of inhibin B production in response to hCG stimulation. Luteinized GC function, with respect to inhibins, activin A, and P production, was not influenced by the presence or absence of an oocyte and did not correlate with fertility outcome. However, follicle size did influence rates of local hormone production.

Follicular fluid levels of inhibin A, inhibin B, and activin A levels reflect changes in follicle size but are not independent markers of the oocyte's ability to fertilize.

OBJECTIVE: To investigate the biochemical relationship between follicular/oocyte maturity and follicular inhibins and activin levels. DESIGN: Prospective study. SETTING: Research laboratory in university hospital. PATIENT(S): Thirty-five women undertook IVF/ICSI program. INTERVENTION(S): Individual follicular fluid aspirations, oocyte isolation, follicular fluid storage. MAIN OUTCOME MEASURE(S): Inhibin A, inhibin B, and activin A concentrations, oocyte retrieval, and fertility outcome. RESULT(S): Inhibin A, inhibin B, and activin A concentrations varied from 7.9 to 436 ng/mL, 9.7 to 786 ng/mL, and 1.7 to 267.9 ng/mL, respectively. There was no change of inhibin A concentrations, whereas inhibin B and activin A concentrations dropped dramatically as the follicles enlarged. Total follicular content of inhibin A and activin A increased, and inhibin B remained constant. Both inhibin A and inhibin B levels were significantly higher in those follicles from which an oocyte could be recovered, but they did not differ with respect to subsequent oocyte fertilization. CONCLUSION(S): Inhibin A is actively produced throughout follicular growth to retain a set concentration. In contrast, inhibin B appears not to be actively produced, and the concentration drops as follicles enlarge. Activin A concentrations also decrease, but there is some extra synthesis. Higher levels of inhibin A and B are associated with oocyte presence but not with fertilization rates.