Human chorionic gonadotropin localization and morphometric characterization of human granulosa-luteal cells obtained during in vitro fertilization cycles

Morphometric and ultrastructural analysis of human granulosa cells after gonadotrophin-releasing hormone agonist or antagonist

Morphological features of granulosa cells can reflect their functional status. The present study was aimed at comparing possible differences in the fine structure of human granulosa cells exposed to gonadotrophin-releasing hormone (GnRH) agonist or antagonist treatment during ovarian stimulation. Cells were obtained from follicular aspirates of 21 women treated with recombinant follicle-stimulating hormone (rFSH) plus either a GnRH agonist or a GnRH antagonist. Conventional light microscopy procedures and computerized image analysis systems were used to identify different cell type morphological patterns and to quantify different cells distribution. Two morphologically distinct granulosa cell populations, defined as large/pale and small/dark cells, were identified and a different distribution in the two groups of women under investigation was found: a significantly higher percentage in large/pale cells was detected in the agonist-treated women (P<0.05), whereas the percentage of small/dark cells was significantly higher in the antagonist-treated group (P<0.05). Ultrastructural observations showed the presence in both cell populations of typical hallmarks of steroidogenic cells, highlighting signs of functional activity in the large/pale cell population. Further investigations are needed to define the possible clinical significance of these morphological findings.

Expression of sex hormone-binding globulin (SHBG) in human granulosa-lutein cells

Sex hormone-binding globulin (SHBG) was classically thought to be a plasma steroid-carrying protein of hepatic origin, but recently, locally produced, membrane-bound SHBG has been shown to influence cell functions in several steroid-responsive tissues. In the ovary, SHBG is known to be present in the follicular fluid, but information about a possible intracellular presence of SHBG in this organ is still very scarce. In this study the presence of SHBG was assessed by immunohistochemistry in human granulosa-lutein cells (GLC) collected by follicle puncture for in vitro fertilization. SHBG was detected in the cytoplasm of GLC before and after in vitro culture for up to 96 h. The presence of full-length SHBG messenger RNA was demonstrated in GLC by reverse transcription-polymerase chain reaction (RT-PCR) in both cultured and uncultured cells. These results demonstrate a local synthesis of SHBG in GLC and raise the question of the physiological significance of these findings in follicular physiology.

Subpopulations of human granulosa-luteal cells obtained from gonadotropin- or gonadotropin-releasing hormone agonist/gonadotropin-treated follicles in in vitro fertilization-embryo transfer cycles

PURPOSE

Our purpose was to find the differences in granulosa-luteal cells obtained from gonadotropin-versus gonadotropin-releasing hormone (GnRH) agonist/gonadotropin-treated follicles in in vitro fertilization-embryo transfer (IVF-ET) cycles.

METHODS

Granulosa-luteal cells were obtained from 45 follicles of women undergoing IVF-ET with gonadotropin releasing hormone (GnRH) agonist and human menopausal gonadotropin (hMG) and from 45 follicles of women with hMG IVF-ET cycles. Subpopulations of granulosa-luteal cells were observed by computerized image analysis in which human chorionic gonadotropin (hCG) was localized using immunoperoxidase staining.

RESULTS

The luteinized granulosa-luteal cells from hMG-treated follicles were larger than those from GnRH agonist/hMG-treated follicles. The hMG-treated follicles contained more hCG-stained cells, particularly those with cytoplasmic hCG localization.

CONCLUSIONS

We found differences in morphometric characteristics and hCG localization in granulosa-luteal cells obtained from hMG-versus GnRH agonist/hMG-treated follicles. We presume that the results indicate the influence and importance of luteal-phase support on the clinical pregnancy rate in GnRH agonist/hMG-treated IVF-ET cycles.

Subpopulations of human granulosa-luteal cells obtained during early timed and during normally timed follicular aspiration in in-vitro fertilization-embryo transfer cycles

OBJECTIVE

To find the differences between human granulosa-luteal cells obtained during early timed follicular aspiration to prevent severe ovarian hyperstimulation syndrome (OHSS) and during normally timed follicular aspiration.

DESIGN

Retrospective analysis of clinical laboratory data.

SETTING

In vitro fertilization unit, University Department of Obstetrics and Gynecology, Ljubljana, Slovenia.

PATIENT(S)

Twenty women undergoing IVF-ET at high risk for OHSS.

INTERVENTION(S)

Cells were obtained from the follicles of women who were stimulated with hMG and hCG during an early timed follicular aspiration of one ovary, 10-12 hours after hCG, and during a normally timed follicular aspiration of the contralateral ovary, 32-36 hours after hCG administration.

MAIN OUTCOME MEASURE(S)

Subpopulations of granulosa-luteal cells were observed by computerized image analysis in which hCG was localized using immunoperoxidase staining.

RESULT(S)

Early timed follicular aspirates contained no oocytes and only a scant number of granulosa cells. Granulosa-luteal cells were smaller than those from normally timed follicular aspirates. We identified three subpopulations in early timed follicular aspirates: nonluteinized, small luteinized, and medium luteinized cells. In normally timed follicular aspirates, four subpopulations were identified, including large luteinized cells. The normally timed follicular aspirates contained more hCG-stained cells. Three staining types of hCG localization were found: on the surface membrane, on the surface membrane and within the cytoplasm, and only within the cytoplasm of cells from normally timed follicular aspirates. Early timed follicular aspirates contained only cells with membrane hCG localization.

CONCLUSION(S)

We found differences in morphometric characteristics and hCG localization between human granulosa-luteal cells obtained during early timed follicular aspiration to prevent severe OHSS and during normally timed follicular aspiration.

Direct gamete uterine transfer in patients with tubal absence or occlusion

PURPOSE

Our aim was to examine the potential of the uterine cavity to affect fertilization and early embryo development.

DESIGN

A prospective IRB-approved protocol for patients fulfilling study eligibility criteria was used.

METHODS

Patients studied included those with primary or secondary infertility, aged less than 38 years, with no history of severe male-factor infertility, and with hysterosalpingogram- and laparoscopic-confirmed bilateral proximal tubal occlusion. Superovulation induction was accomplished with a combination of GnRH agonist and menotropins, with serum hormonal and sonographic monitoring. Within 24 hr prior to, and again at the time of, ovulatory hCG administration, progesterone (P4) was given. Sonographic-guided transvaginal retrieval was performed 35 hr after hCG. Between four and six oocytes were returned to the uterine cavity, admixed with sperm, immediately following retrieval. Luteal support consisted of daily P4 administration.

RESULTS

Of the 20 patients recruited for the study, all completed the retrieval and transfer procedure. A total of four clinical pregnancies was achieved, with one early first-trimester loss, one late first-trimester loss (Trisomy 14), and two healthy term infants delivered. IVF of surplus oocytes demonstrated a 82.5% fertilization rate and 66.7% cleavage following cryopreservation.

CONCLUSIONS

Human fertilization can be achieved through direct uterine transfer of gametes. Furthermore, administration of P4 prior to the ovulatory dose of hCG is compatible with in vitro or in vivo fertilization and implantation.

Subpopulations of human granulosa-luteal cells in natural and stimulated in vitro fertilization-embryo transfer cycles

OBJECTIVE

To find out the differences between human granulosa-luteal cells derived from natural and stimulated IVF-ET cycles.

DESIGN

Cells were obtained from dominant follicles of 52 women with natural cycles in whom preovulatory hCG was given when the follicle was mature and from 50 dominant follicles of women undergoing IVF-ET with hMG and hCG.

SETTING

In Vitro Fertilization Unit, University Department of Obstetrics and Gynecology Ljubljana, Slovenia.

MAIN OUTCOME MEASURE

Four subpopulations of cells were observed by computerized image analysis in which hCG was localized using immunoperoxidase staining.

RESULTS

The nonluteinized granulosa cells from natural cycles were larger than those from the stimulated ones. In luteinized cell types, there was no difference in cell area between natural and stimulated cycles. Three staining types of hCG localization were found: on the surface membrane, on the surface membrane and within the cytoplasm, and within the cytoplasm alone. The hCG stained cells from natural cycles were larger than the ones from stimulated cycles. The natural developing follicles contained more hCG stained cells than the stimulated ones. The follicles with fertilizable oocytes had more cells with cytoplasmic hCG localization. Only in natural cycles was there was a correlation between follicular fluid hCG levels and the percentage of the hCG stained cells.

CONCLUSION

We found differences in morphometric characteristics and hCG localization between human granulosa and granulosa-luteal cells obtained from natural and stimulated IVF-ET cycles.

Influence of follicular phase duration on human granulosa-luteal cell subpopulations in natural and stimulated IVF-ET cycles

OBJECTIVES

To observe the granulosa-luteal cell subpopulations presented within follicular aspirates concerning duration of the follicular phase and the type of IVF protocol.

DESIGN

Cells were obtained from dominant follicles of 40 women with natural IVF-ET cycles, in which preovulatory hCG was given when the follicle was mature, and from 40 follicles of 32 women with hMG and hCG stimulated IVF-ET cycles. Granulosa-luteal cell subpopulations were observed by computerized image analysis in which hCG was localized using immunoperoxidase staining.

RESULTS

(1) The nonluteinized granulosa cells from natural developing follicles were larger than those from stimulated ones regardless of the follicular phase duration. (2) The size of each luteinized cell subpopulations was influenced neither by the two IVF protocols nor by the follicular phase duration. (3) The hCG stained cells from natural developing follicles were larger than the ones from stimulated follicles and their relative number in aspirates was higher. Cell areas and distribution were not influenced by the duration of follicular phase. (4) In stimulated conditions, hCG stained cells became larger if follicular phase was longer.

CONCLUSIONS

Duration of the follicular phase influences the immunocytochemical hCG localization and the morphometric characteristics of granulosa-luteal cell subpopulations presented within natural developing follicles and stimulated ones.

Elevated serum progesterone levels on the day of human chorionic gonadotropin administration in in vitro fertilization cycles do not adversely affect embryo quality

OBJECTIVE

To assess the effect of an elevated serum P level on the day of hCG administration in an IVF cycle on resulting embryos by evaluating their performance at subsequent frozen ET.

DESIGN

A retrospective study.

PARTICIPANTS

Ninety-six consecutive patients undergoing frozen ET cycles were studied in a tertiary care center.

MAIN OUTCOME MEASURES

Serum obtained on the day of hCG administration in an IVF cycle was assayed for E2 and P by RIA. The main outcome measured was the development of a clinical pregnancy in a subsequent frozen ET cycle.

RESULTS

Using a previously described breakpoint in serum P concentration of 0.9 ng/mL (2.86 nmol/L), 8 of 69 (11.6%) frozen ETs in which embryos from low P level IVF cycles were transferred and 7 of 27 (25.9%) frozen ETs of embryos from elevated P level IVF cycles were transferred resulted in the development of clinical pregnancies. Although this does not clearly demonstrate superiority of embryos obtained from elevated P cycles, employing a power calculation, the probability that the pregnancy rate in the elevated serum P group is at least equal to the observed rate in the low P group is 92.8%.

CONCLUSION

These data suggest that an elevated serum P level on the day of hCG administration does not adversely affect the quality of oocytes or resulting embryos.

Steroidogenesis in vitro of human granulosa-luteal cells pretreated in vivo with two gonadotropin releasing hormone analogs employing different protocols

We have previously observed impaired progesterone accumulation in vitro in response to human chorionic gonadotropin (hCG) by cells pretreated in vivo with a gonadotropin releasing hormone analog (GnRH-a). The present study was conducted in order to evaluate different protocols for GnRH-a in in vitro fertilization (IVF), employing two different available analogs. Granulosa-luteal cells were collected at ovum pick-up and stimulated with hCG. Buserelin (Bus) was employed as long (Bus-L) and short (Bus-S) protocol, and Leuprolide (Leu) was also used as long (Leu-L) and short (Leu-S) protocol. Progesterone accumulation in vitro was compared with cells treated with clomiphene citrate (CC) and gonadotropins. Maximal progesterone production was observed on culture day 6 using Bus-L in comparison to day 4 when clomiphene citrate was employed. While Leu-S showed a similar pattern of progesterone accumulation to clomiphene citrate, Leu-L and Bus-S had an intermediate pattern. The response to hCG was maximal on day 4 for the clomiphene citrate- and Leu-S-treated cells, while the rest of the protocols had a peak on day 6. In addition, hCG consistently stimulated progesterone production in all protocols except in Bus-L. These results confirm an altered progesterone accumulation in vitro when GnRH-a are used. The effect seems to be more evident in long protocols, especially when buserelin is used, suggesting a higher accumulation of the analog in follicular fluid.

Steroidogenesis in vitro of human granulosa-luteal cells pretreated in vivo with gonadotropin-releasing hormone analogs

A modulatory role for gonadotropin-releasing hormone (GnRH) on granulosa cell functions has been demonstrated in animals. Because human granulosa cells have specific receptors for GnRH, we have compared steroidogenesis in vitro of cells pretreated in vivo with GnRH analogs (GnRH-a) with other ovarian stimulation regimens used in in vitro fertilization (IVF) cycles. Cells from 13 patients treated with a GnRH-a for 26.8 +/- 1.1 days during pituitary desensitization and ovarian stimulation with gonadotropins were cultured. Their steroidogenesis was evaluated in basal conditions as well as after stimulation with follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG). Granulosa-luteal cells from 9 women treated with a combination of clomiphene citrate (CC) and gonadotropins were also cultured. Estradiol production in response to FSH was stimulated only in the GnRH-a-treated cells. Basal, FSH-, and hCG-induced progesterone (P) accumulation was higher in the CC-treated cells. The peak of P production was delayed 2 days in the GnRH-a-treated group. Only cells pretreated in vivo with GnRH-a accumulated 20 alpha-hydroxyprogesterone in culture. The results of the present study suggest that the use of GnRH-a during a long period of time for IVF affects the steroidogenic pathway of human granulosa-luteal cells. It seems that, at least in part, this change is due to the stimulation of the metabolizing enzyme 20 alpha-hydroxysteroid dehydrogenase by GnRH-a.