The effect of leuprolide acetate on steroidogenesis by granulosa and theca cells in vitro

Leuprolide acetate reduces both in vivo and in vitro ovarian steroidogenesis in infertile women undergoing assisted reproduction

Despite the probable inhibitory effects of GnRH analogues on ovarian steroidogenesis in vitro, their association with assisted reproduction protocols shows favorable results. This suggests that there are important differences in the behaviors of these drugs when administered in vivo versus in vitro. To clarify these differences, this study was designed to analyze the effect of leuprolide acetate (LA) on ovarian steroidogenesis in women undergoing In Vitro Fertilization (IVF). A prospective, randomized open label study was conducted on 14 women (26-35 years): seven receiving only gonadotrophins (Group 1) and seven receiving gonadotrophin plus LA at 1mg/day (Group 2). The LA in vivo effect was determined with serum and follicular fluid (FF) samples and via luteinized granulosa cell cultivation (GCC), where cells were obtained during oocyte retrieval after ovarian hyperstimulation. In vitro analysis was performed via addition of LA to GCC only for Group 1 (without LA) at progressively higher concentrations (0, 10(-12), 10(-9) and 10(-6)M). In vivo, the main observation was a reduction in androgen production in Group 2, represented by lower androstenedione production in FF (G1=6479+/-3458; G2=3021+/-1119 ng/ml; p=0.04) and a lower testosterone peak in GC at 96h (G1=0.64+/-0.12 ng/ml; G2=0.50+/-0.19 ng/ml; P=0.02), but a higher fertilization rate (G1=67%; G2=83%; p=0.009). In vitro, testosterone, estradiol and progesterone were also reduced by LA, even though this reduction occurred for progesterone only at the highest LA dosage (10(-6)M; 606.0+/-114.3 ng/ml versus 1524.0+/-246.5 ng/ml; p=0.02). Results show that LA reduces ovarian steroidogenesis in vivo by essentially inhibiting androgen synthesis; whereas, in vitro, ovarian steroidogenesis is reduced overall.

Impact of leuprolide acetate on luteal phase function in women undergoing controlled ovarian hyperstimulation and intrauterine insemination

OBJECTIVE

To determine if the combination of leuprolide acetate (LA) and human menopausal gonadotropin (hMG) results in luteal phase dysfunction.

DESIGN

A prospective, randomized clinical trial.

SETTING

A tertiary care university fertility center.

PATIENT(S)

One hundred thirty-five couples with various etiologies of infertility.

INTERVENTION(S)

Patients were prospectively randomized to receive either hMG and intrauterine insemination (IUI) or luteal phase down-regulation with LA, hMG, and IUI.

MAIN OUTCOME MEASURE(S)

Serum luteal phase progesterone (P) and luteal phase estradiol (E2) were obtained 9 days after hCG administration. Twenty-four-hour urinary P and luteinizing hormone (LH) were analyzed 9 days after human chorionic gonadotropin (hCG). Endometrial biopsies were performed 11 days after hCG and evaluated for luteal phase defects (LPD) using Noyes' criteria.

RESULT(S)

No significant differences in the incidence of LPD (11.9% vs. 13.9%), cycle fecundity (16.6% vs. 16.3%), or luteal phase hormone profiles were observed between the groups receiving and not receiving LA. A significant difference in E2 levels (on the day of hCG administration) between cycles with a luteal phase defect (967 pg/mL +/- 106) and without a luteal phase defect (1,422 pg/mL +/- 83) was observed (P<.05).

CONCLUSION(S)

Pituitary down-regulation with LA combined with hMG did not result in luteal phase dysfunction. The E2 levels on the day of hCG administration in both groups were lower in women with documented luteal phase defects.

Effect of in vivo GnRH agonist and GnRH antagonist on hCG and insulin-stimulated progesterone production by human granulosa-lutein cells in vitro

PURPOSE

To investigate hCG and insulin-stimulated progesterone (P) production by human granulosa-lutein cells (hGLC) in vitro.

METHODS

hGLCs were isolated from patients undergoing IVF-ET cycles in which GnRH agonist or GnRH antagonist was used to prevent a midcycle gonadotropin surge. The cells were cultured for 3 days, and then treated with hCG 0.5, 1, and 10 IU/I, and insulin 0.01, 0.1, and 1 microM in serum free conditions. In vitro P production was measured by enzyme immunoassay.

RESULTS

hCG stimulated P production by hGLCs from cycles in which GnRH antagonist was used, but a blunted response was seen in GnRH-agonist treated cycles. Insulin-stimulated P production was similar in cells from cycles in which GnRH-agonist or GnRH-antagonist treatment was used.

CONCLUSIONS

Because insulin and hCG may share common pathways beyond the level of receptor activation, we hypothesize that GnRH agonist, but not GnRH antagonist, may affect the expression and/or activation of LH receptors in the hGLCs.

Gonadotropin-Releasing Hormone Antagonists

Gonadotropin-releasing hormone (GnRH) antagonists are now widely used in protocols of patients with controlled ovarian hyperstimulation to treat infertility. By competitively binding to the pituitary GnRH receptor, they lead to a rapid suppression of gonadotropins and consecutively sex hormones. In the past, GnRH agonists have been exclusively used for these patients, with the disadvantage of an initial rise of gonadotropins--the flare-up effect. Several trials comparing the agonistic and antagonistic analogs of GnRH found no significant differences in oocyte quality, fertilization and pregnancy rates. Slightly lower implantation and pregnancy rates, and estradiol levels, in patients treated with GnRH antagonists has raised concern about eventual extrapituitary adverse effects. However, no convincing evidence has yet been found for any detrimental ovarian effects of GnRH antagonists. The lower rate of ovarian hyperstimulation syndrome, a potentially severe disadvantage of infertility treatment, is a positive feature of GnRH antagonists. The key point is that GnRH antagonists have been proven to be as effective and safe as GnRH agonists. This broadens the spectrum of indications for GnRH antagonists to sex hormone-dependent disorders like endometriosis, uterine fibroids, and gynecological cancers such as breast and ovarian cancer.

Leuprorelin. A review of its pharmacology and therapeutic use in prostatic cancer, endometriosis and other sex hormone-related disorders

Leuprorelin (leuprolide acetate) is a gonadotrophin-releasing hormone (GnRH) analogue used to treat a wide range of sex hormone-related disorders including advanced prostatic cancer, endometriosis and precocious puberty. It acts primarily on the anterior pituitary, inducing a transient early rise in gonadotrophin release. With continued use, leuprorelin causes pituitary desensitisation and/or down-regulation, leading to suppressed circulating levels of gonadotrophins and sex hormones. Clinical trials in men with advanced prostatic cancer demonstrate that leuprorelin (usually monthly depot injections of 3.75 or 7.5 mg) is less likely to cause serious adverse cardiovascular effects than diethylstilbestrol, and has comparable efficacy to bilateral orchiectomy or other GnRH analogues. Therefore, the choice between leuprorelin and orchiectomy may be made on the basis of the patient's treatment preference, along with specific patient characteristics and cost implications. Monthly intramuscular or subcutaneous administration of depot leuprorelin 3.75 mg was superior to placebo, and comparable to oral danazol 800 mg/day or intranasal buserelin 900 micrograms/day, in achieving objective and subjective responses in women with endometriosis. Thus, leuprorelin is an effective alternative to other treatments for women with endometriosis, but the recommended duration of its use in this clinical setting is limited to 6 months because it reduces bone mineral density. In children with central precocious puberty, leuprorelin (usually monthly intramuscular or subcutaneous injections of depot leuprorelin 3.75 to 15mg) decreases mean growth velocity and signs of sexual maturation and increases predicted adult height compared with baseline measurements. Although effects on final adult height are predicted from available data and require confirmation in long term follow-up studies, the absence of effective alternatives to GnRH analogues makes leuprorelin a first-line therapy for children with this rare disease. In women with uterine leiomyomata, monthly intramuscular administration of depot leuprorelin 3.75 mg for 6 months markedly reduces uterine volume and fibroid-related symptoms, but, as with other GnRH analogues, these effects dissipate following discontinuation of the drug. As adjuvant therapy in women undergoing in vitro fertilisation or gamete intrafallopian transfer, leuprorelin (usually 0.5 to 1 mg/day subcutaneously) reduces the risk of cancelled cycles for oocyte retrieval by preventing premature luteinisation. While some studies demonstrate an improvement in intermediate end-points such as increased number of mature oocytes retrieved and embryos available for transfer, a significant effect has not been demonstrated on the rate of live births per stimulated cycle.(ABSTRACT TRUNCATED AT 400 WORDS)

Addition of a gonadotropin releasing hormone (GnRH) antagonist and exogenous gonadotropins to unstimulated in vitro fertilization (IVF) cycles: physiologic observations and preliminary experience

PURPOSE

To describe our preliminary experience with the addition of a GnRH antagonist (Nal-Glu) and exogenous gonadotropins (follicle stimulating hormone; FSH) to unstimulated IVF cycles.

METHOD

Seven spontaneously ovulatory women underwent eight unstimulated IVF cycles at our institution. They were treated with a single dose of Nal-Glu, 50 micrograms/kg, or with a combination of Nal-Glu, 50 micrograms/kg, and exogenous FSH, 150-300 IU, during the late follicular phase of spontaneous cycles. They then received 10,000 IU of human chorionic gonadotropin (hCG) to time accurately follicle aspiration in unstimulated IVF cycles.

RESULTS

Two women underwent three cycles with Nal-Glu alone on the day of hCG administration. One pregnancy resulted. Five women underwent five cycles with 3 to 6 days of daily Nal-Glu and FSH. Four of these cycles resulted in aspiration after the FSH dose was increased to 300 IU. Nal-Glu and FSH allowed continued development of the dominant follicle without the occurrence of luteinizing hormone (LH) surge.

CONCLUSIONS

(1) Nal-Glu alone given 18 hr prior to hCG did not interfere with continued follicle viability or with the attainment of pregnancy. (2) Simultaneous Nal-Glu and FSH allowed for continued growth and development of the dominant follicle without the occurrence of an LH surge. (3) This preliminary experience confirms the feasibility of this novel approach, which may ultimately enhance the efficacy of unstimulated IVF cycles by eliminating premature ovulation and maximizing control of gonadotropin delivery to the developing follicle.

The comparison of two gonadotropin-releasing hormone agonists in an in vitro fertilization program

OBJECTIVE

To compare two gonadotropin-releasing hormone agonists (GnRH-a), buserelin acetate and leuprolide acetate [LA], used in combination with gonadotropins in ovarian stimulation for in vitro fertilization (IVF).

DESIGN

Randomized prospective study.

SETTING

Assisted Reproduction Unit of the Hospital Clínic i Provincial in Barcelona.

PATIENTS

Thirty-five pairs of IVF patients who were matched on age, indication, and number of attempts. These women were randomized to receive either buserelin acetate plus gonadotropins (group B) or LA plus gonadotropins (group L).

MAIN OUTCOME MEASURES

Luteolysis, ovarian response, and IVF outcome.

RESULTS

The mean time for total ovarian arrest and the total dose of gonadotropins and estradiol levels on the day of human chorionic gonadotropin administration were similar in the two groups of patients. The number of follicles punctured, the number of oocytes retrieved, and the percentage of mature oocytes in group L were significantly higher. The number of embryos suitable for replacement and cryopreservation was higher in group L compared with group B approaching statistical significance.

CONCLUSION

Our results warrant further studies to compare different GnRH-a as therapeutic tools in IVF.