Reversible downregulation of endocrine and germinative testicular function (hormonal castration) in the dog with the GnRH-agonist azagly-nafarelin as a removable implant "Gonazon"; a preclinical trial.

Downregulation of anterior pituitary GnRH-receptors by application of a slow release GnRH-implant offers an effective and reversible alternative to surgical castration of the male dog. Aim of the present study was to test the efficacy and the underlying mechanisms of a new non-biodegradable controlled-release device implant (Gonazon((R)), Intervet, containing 18.5mg of the GnRH-agonist Azagly-Nafarelin). Eight male beagle dogs were implanted s.c. at the para-umbilical region. In four dogs implant removal was after 180 days (group 1), in the other four dogs after 365 days (group 2). Eleven weeks after implantation availability of LH was reduced (p<0.0001) by 70%. After an initial increase lasting for about 4 days, testosterone (T) and estradiol (E2) concentrations decreased (p<0.0001) to basal levels within 17.5+/-8.4 days. Size of testes was decreased by about 82% after 17 weeks, size of prostate by about 46% after 5 weeks (p<0.0001). Five to 7 weeks after implantation all dogs were aspermic. Testosterone and estradiol concentrations, together with testicular and prostatic size remained suppressed in all dogs in group 1 and one dog of group 2 until implant removal. The other three dogs of group 2 escaped from down-regulation between 223 and 324 days. Effects on the availability of LH, T, E2 and on testicular and prostatic size were fully reversible after implant removal or escape from down-regulation. In six dogs semen quality was back to pre-treatment values after about 29 weeks, however, one dog developed oligozoospermia while another one stayed azoospermic, probably due to an obstruction within the epididymal duct.

Controlled delivery of a GnRH agonist by a silastic implant (Gonazon) results in long-term contraception in queens.

Many female cats are spayed to prevent problems associated with calling and unwanted pregnancies. This study describes the safety and efficacy of an alternative approach, using an azagly-nafarelin containing implant (Gonazon) inserted subcutaneously in the neck of six treated queens for 3 years. These six queens together with six controls were permanently housed with vasectomized tom cats, and changes in progesterone concentrations were used to document the contraceptive efficacy of Gonazon. All six control queens ovulated regularly throughout the treatment period (3 years), as shown by regular changes in progesterone concentration. Sixteen ovulatory cycles were observed in each control throughout the study. In Gonazon treated queens, during the week following implant placement, two queens displayed a treatment-induced rise in progesterone concentration. Later on, all treated queens continuously displayed low progesterone concentrations until 3 years post-implant insertion, with the exception of a single isolated episode (at approximately 2.5 years of treatment), of follicular luteinization in two queens. In all queens, azagly-nafarelin concentrations peaked in the week following implant insertion remained high for 1 month and later decreased slowly. After 2.5 years of treatment, azagly-nafarelin concentrations were still greater than 150 pg/ml in 3/6 queens. During a 6-month long extension of the study (36-42 months post-treatment), all queens (treated and controls) were run with intact tom cats. None of them conceived. Following autopsy, ovarian weight and diameter of the uterine horns of 3/6 treated queens were shown to be similar to those of the controls. In conclusion, this study demonstrated that Gonazon efficiently prevented ovulation in queens (100%) for 3 years. Return to fertile heat was not observed towards the end of treatment. However, in half of the treated queens, reversibility of the treatment induced effects on the genital tract was demonstrated.

Recrudescence of spermatogenesis in the dog following downregulation using a slow release GnRH agonist implant.

The present study examined the degree to which downregulation with a GnRH agonist impaired spermatogenesis and the time course of morphological and hormonal changes that occurred during recrudescence of spermatogenesis. Using a control group (group 1, n = 5) of dogs, the effect of a removable slow release GnRH-agonist implant was investigated in beagle dogs (group 2, n = 30). The implant was removed after 5 months (week 0) and three to four dogs were castrated at weeks 0, 3, 6, 9, 12, 15, 18, 21 and 24. The degree of downregulation and recrudescence of spermatogenesis was assessed by evaluation of 200 tubular cross-sections, resulting in an assigning of dogs of group 2 to testis developmental groups (DG) according to the most developed germ cell observed: DG A, spermatocytes; DG B, round spermatids; DG C, elongating spermatids and DG D, elongated spermatids. Downregulation led to an arrest of spermatogenesis at the level of spermatogonia/primary spermatocytes. The time course of recrudescence showed high individual variations and the number of dogs falling into DG A, B, C and D was 4, 3, 6 and 17 respectively. Spermatogenesis in group 2, DG D was not different from group 1 (control). In DG A, mean area of Leydig-cell nuclei was lower (p < 0.001) than in the other DG and group 1 and resembled that of juvenile dogs (group 3, n = 3); nuclei of Sertoli cells had changed from more flat/polygonal (group 1, group 2, DG C and D) to round/ovoid and had moved to a more luminal position. As indicated by basal testosterone (T), luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations at implant removal, full downregulation had been obtained. Testosterone, LH and FSH concentrations [X(g) (DF), ng/ml] increased (p < 0.05) from implant removal to DG B [T: 0.1 (1.24) vs 2.12 (2.31); LH: 0.2 (2.15) vs 1.11 (1.7); FSH: 0.37 (3.50) vs 6.37 (1.68)] and were more or less constant thereafter indicating that onset of spermatogenesis was related to an increase of plasma T occurring in a very narrow time window. Following GnRH implantation, the size of the testes and the prostate decreased by approximately 55% (p < 0.001), they increased to sizes similar to pre-treatment values following implant removal.

Caspase-3 gene expression in human luteinized granulosa cells is inversely correlated with the number of oocytes retrieved after controlled ovarian stimulation.

Granulosa cells control oocyte maturation through paracrine signalling and changes to the microenvironment around the oocyte. Apoptosis occurs as a physiological mechanism of granulosa cell renewal, but how it relates with the ovarian response to induced ovulation is still unclear. Therefore, this study evaluated apoptosis-related gene expression levels in granulosa cells of patients undergoing controlled ovarian stimulation. We enrolled prospectively 59 consecutive IVF patients referred to a tertiary academic hospital for couple infertility treatment. Luteinized granulosa cells were isolated from follicular fluid and the RNA was extracted, reverse-transcribed and the gene expression of apoptosis inducers (caspase-3, caspase-8 and bax) and inhibitor (Bcl-2) was quantified by real-time polymerase chain reaction. Caspase-3 gene expression correlated negatively with the number of pre-ovulatory follicles (Spearman's r = -0.308), the number of collected oocytes (r = -0.451), the number of mature oocytes (r = -0.526), the number of fertilized oocytes (r = -0.439) and the number of viable embryos (r = -0.443, all statistically significant at p < 0.02 level). No such associations were found with caspase-8, bax or bcl-2. These preliminary findings suggest that increased caspase-3 gene expression in granulosa cells is associated with a worse ovulatory response in humans.

Transdermal delivery of peptides by iontophoresis.

Transdermal administration by iontophoresis (enhanced transport via the skin using the driving force of an applied electric field) has been successfully demonstrated but no formal relationship between peptide sequence/structure and efficiency of delivery has been established. There are notable examples, such as the lipophilic leutinizing hormone releasing hormone (LHRH) analogs, Nafarelin and Leuprolide, that exhibit down-regulation of their own transport across the skin under the influence of an iontophoretic current. The hypothesis that this phenomenon is due to neutralization of the skin's net negative charge by these cationic peptides was examined with LHRH oligopeptides. The impact of these compounds on the electroosmotic flow of solvent into the skin, which is induced by iontophoresis and which contributes significantly to the electrotransport of large, positively charged ions, was examined and quantified. Close juxtaposition of cationic and lipophilic residues profoundly inhibited electroosmosis and, presumably, peptide flux. The results indicate that the lipophilicity of the oligopeptides facilitates van der Waals interactions with hydrophobic patches along the transport route, thereby permitting the positively charged oligopeptide to interact with carboxylate side chains that give the skin its net negative charge at neutral pH. The lipophilic, cationic oligopeptide, therefore, becomes anchored in the transport path, neutralizing the original charge of the membrane, and completely altering the permselective properties of the skin.

Maturation of gonadotropin and sex steroid responses to gonadotropin-releasing hormone agonist in males.

We have previously demonstrated that a single dose of the GnRH agonist nafarelin stimulates both gonadotropin and sex steroid secretion in adult men and women. In order to define the maturational steps involved in this response, we tested the effect of nafarelin on LH, FSH, testosterone (T), and estradiol (E2) secretion over 24 h in four groups of males: prepubertal (P1; n = 4), early pubertal (P2; n = 8), and midpubertal boys (P3; n = 4) with variations in the timing of puberty, and normal young adult males (P4; n = 10). Nafarelin stimulated rapid gonadotropin release in all groups, but the pattern of LH response varied. In prepubertal and pubertal boys, LH levels peaked 3-4 h after nafarelin and declined by 50% or more at 24 h post nafarelin. By contrast, adults reached an initial LH peak at 1 h, and LH secretion was sustained with levels 24 h post nafarelin equivalent to those during the early response phase. Nafarelin stimulated T secretion in all groups, but the response was greatest in groups P3 and P4; the maximal incremental rise (delta) in T was 1.2 +/- 0.5, 4.4 +/- 1.0, 18.8 +/- 5.4, and 15.3 +/- 1.4 nmol/L in P1, P2, P3, and P4 males, respectively (analysis of variance: F = 14.4, P < 0.001). E2 concentrations increased much more in adults than in the other groups post nafarelin: delta E2 was 5.5 +/- 1.1, 22.1 +/- 14.7, 83.9 +/- 47.5, and 323.8 +/- 14.7 pmol/L in the P1, P2, P3, and P4 groups, respectively (F = 71.1, P < 0.001). Similarly, the delta E2/delta T ratio was significantly greater in adult males than in less mature males. This developmental pattern of response to nafarelin suggests that male pubertal maturation involves increase of the gonadotrope LH readily releasable and reserve pools. The dissociation of E2 from T responses to nafarelin during puberty suggests that aromatase activity does not fully mature in males until puberty is complete. These findings indicate that a single dose of the GnRH agonist nafarelin is a promising means of assessing the maturation of the pituitary-gonadal axis in males.

Effects of gonadal suppression on the regulation of parathyroid hormone and 1,25-dihydroxyvitamin D secretion in women.

Although a causal association between estrogen deficiency and bone loss has been established for many years, the mechanism by which estrogen deficiency leads to bone loss is unclear. Estrogen deficiency could induce bone loss either by a direct effect on bone cells to modify the production of bone-resorbing cytokines or by altering the production or response to calcium regulatory hormones such as PTH and 1,25-dihydroxyvitamin D. To assess the effects of ovarian hormones on calcium regulatory hormones, we evaluated the ability of calcium to suppress PTH secretion and the ability of PTH to increase serum 1,25-dihydroxyvitamin D and whole blood ionic calcium levels in women before and after GnRH analog-induced ovarian suppression. Sixteen women with endometriosis underwent i.v. infusion of calcium (1.1 mg calcium gluconate/cc in 5% dextrose) at a rate of 4 cc/kg x h (n = 7) or human PTH-(1-34) (Parathar) at a dose of 0.55 U/kg x h (n = 9) before and after 6 months of suppression of ovarian function with the GnRH analog nafarelin acetate (200 microg, intranasally, twice daily). Initial infusions were performed between days 6-10 of the menstrual cycle. Serum PTH and whole blood ionic calcium levels were measured at -20, -10, and 0 min and then every 10 min for 2 h during i.v. calcium infusions. Whole blood ionic calcium and 1,25-dihydroxyvitamin D levels were measured every 6 h for 24 h during i.v. human PTH-(1-34) infusions. Serum estradiol levels were markedly suppressed by nafarelin therapy in both groups of women. The relationship between whole blood ionic calcium and serum PTH levels was similar before and during nafarelin-induced ovarian suppression. The net change and rate of rise in serum 1,25-dihydroxyvitamin D levels in response to PTH infusion were similar before and during nafarelin therapy. Peak whole blood ionic calcium and incremental increases in ionic calcium in response to PTH were similar before and during nafarelin therapy. Our data suggest that ovarian suppression does not alter the regulation of PTH secretion in response to calcium, the ability of PTH to stimulate 1,25-dihydroxyvitamin D formation, or the skeletal sensitivity to PTH. These findings suggest that alterations in calcium regulatory hormones by estrogen deficiency are unlikely to play a major role in the pathogenesis of estrogen deficiency bone loss.

Ovarian steroidogenic responses to gonadotropin-releasing hormone agonist testing with nafarelin in hirsute women with adrenal responses to adrenocorticotropin suggestive of 3 beta-hydroxy-delta 5-steroid dehydrogenase deficiency.

Nonclassical 3 beta-hydroxy-delta 5-steroid dehydrogenase (3 beta-HSD) deficiency type of congenital adrenal hyperplasia has been hypothesized to occur in as many as 10-40% of hirsute women, based on the adrenal steroidogenic responses to ACTH. However, diagnostic criteria for this "late-onset" 3 beta-HSD deficiency are not clearly established. Among 40 successive hyperandrogenic women undergoing evaluation of adrenal steroidogenic responses to ACTH, 8 had responses suggestive of 3 beta-HSD deficiency. Since 3 beta-HSD is present in both the ovary and adrenal, we attempted to document the defect in the ovary by stimulating their ovarian function with a gonadotropin-releasing hormone agonist test using nafarelin (6-D-[2-naphthyl]alanine-gonadotropin-releasing hormone). The eight hirsute women had steroid responses to ACTH suggestive of 3 beta-HSD deficiency, namely, the values of the delta 5-steroids, 17-hydroxypregnenolone and dehydroepiandrosterone, 30 and 60 min after ACTH in each hirsute woman were greater than 2 SD above the normal mean. Seven of the eight hirsute women had at least one elevated delta 5/delta 4-steroid ratio; however, only three of the hirsute women had two abnormal ratios. Furthermore, the response of the delta 4-steroid androstenedione and the ratio of androstenedione to cortisol after ACTH were significantly increased in the hirsute women, findings not consistent with 3 beta-HSD deficiency. After nafarelin, five and six hirsute patients had elevated values of the delta 4-steroids androstenedione and 17-hydroxyprogesterone, respectively. No patient had an elevated delta 5/delta 4-steroid ratio after nafarelin. Thus, ovarian steroidogenic responses to nafarelin did not support the diagnosis of 3 beta-HSD deficiency. Rather, they are consistent in most cases with polycystic ovary syndrome due to dysregulation of 17-hydroxylase and 17,20-lyase activities. We propose that increased activity of the enzyme P450c17 alpha in the adrenal cortex is responsible for most of what is often termed late-onset 3 beta-HSD deficiency.

Maturation of the normal pituitary-testicular axis, as assessed by gonadotropin-releasing hormone agonist challenge.

Pilot studies in boys with abnormalities of puberty have suggested that both gonadotropin and sex steroid responses to GnRH agonist undergo characteristic maturational changes. However, it is not known how the pattern of hormonal secretory responses to GnRH agonist changes during normal puberty. Therefore, we have assessed the responses of normal boys at various stages of pubertal development to a single dose of the GnRH agonist nafarelin. Baseline LH, FSH, testosterone (T), estradiol (E2), and steroid intermediates, including 17-hydroxyprogesterone, increased during puberty. LH responses peaked at 3 h in prepubertal (P1; n = 8) and midpubertal (P2; n = 4) boys, at 12 h in late pubertal (P3; n = 8) boys, but earlier (0.5-1 h) in adults (P4; n = 10). LH levels remained high for 24 h in P3-P4. Indexes of both the readily releasable and reserve pools of pituitary LH increased significantly with advancing pubertal stage (P < 0.003). FSH responses differed among groups only at 24 h. Nafarelin stimulated T significantly in groups P2 < P3 < P4. The maximal responses of T were 0.54 +/- 0.25 (+/- SEM), 8.7 +/- 2.9, 18.5 +/- 1.0, and 15.3 +/- 1.4 nmol/L in these respective groups (by analysis of variance, F = 40.5; P < 0.001). However, nafarelin did not stimulate E2 significantly until late puberty; the maximal E2 responses to nafarelin treatment were 17.9 +/- 5.9, 26.7 +/- 8.7, 318 +/- 71.3, and 329 +/- 17.4 pmol/L in P1, P2, P3, and P4 (F = 18.3; P < 0.001). In contrast to E2, most intermediate steroids measured increased significantly in response to nafarelin in stages P2-P4. We conclude that a single dose of the GnRH agonist nafarelin stimulates gonadotropin secretion in normal prepubertal and pubertal males; it also stimulates gonadal steroid production in pubertal males. Pubertal maturation of gonadotrope function appears to involve mainly increases in both the readily releasable and reserve pools of LH. The findings that late pubertal boys had LH responses similar to those of men, but greater T and lesser 17-hydroxyprogesterone outputs are compatible with their pituitary-testicular axis operating at a less down-regulated state than that of adults. The apparently isolated failure of E2 to increase in response to nafarelin in early puberty suggests that maturation of aromatase activity normally does not become appreciable until late puberty. These findings suggest that a single dose of GnRH agonist may provide a simple means of assessing the maturation of the neuroendocrine-testicular axis.

Ovarian hyperandrogynism as a result of congenital adrenal virilizing disorders: evidence for perinatal masculinization of neuroendocrine function in women.

Women with congenital adrenal hyperplasia due to 21-hydroxylase deficiency often have a polycystic ovary-like syndrome, consisting of hyperandrogynism, infertility, menstrual irregularities, and elevated LH levels. This is generally considered secondary to poor control of the congenital adrenal hyperplasia. However, our experience led us to suspect that ovarian hyperandrogenism occurs even when congenital adrenal hyperplasia is well controlled on glucocorticoid therapy. Therefore, we tested the hypothesis that congenital adrenal virilizing disorders result in ovarian hyperandrogenism. We studied eight women with congenital adrenal virilizing disorders, seven with well controlled classic 21-hydroxylase deficiency and one with congenital virilizing adrenal carcinoma removed at 1.7 yr of age. We also studied six women with late-onset 21-hydroxylase deficiency, without signs of congenital virilization. An ovarian source of androgens was assessed after suppressing adrenal function with dexamethasone and then testing pituitary-ovarian function by a GnRH agonist (nafarelin) test. Five women with congenital adrenal virilizing disorders (four with classic 21-hydroxylase deficiency and one with congenital virilizing adrenal carcinoma) and one women with late-onset 21-hydroxylase deficiency had ovarian hyperandrogenism as determined by subnormal suppression of free testosterone after dexamethasone and/or by increased 17-hydroxyprogesterone response to nafarelin while on dexamethasone. All women with congenital adrenal virilization and ovarian hyperandrogenism had elevated LH levels after dexamethasone or elevated early LH response to nafarelin, which suggests that LH excess is the cause of their ovarian hyperandrogenism. This was not the case for the late-onset 21-hydroxylase-deficient woman. Our data are compatible with the hypothesis that congenital adrenal virilization programs the hypothalamic-pituitary axis for hypersecretion of LH at puberty. This is postulated to frequently cause ovarian hyperandrogenism even when adrenal androgen excess is subsequently controlled by glucocorticoid therapy.

Effect of N-methyl substitution of the peptide bonds in luteinizing hormone-releasing hormone agonists.

Each peptide bond in leuprolide (1), deslorelin (13), and nafarelin (24) was separately substituted with N-methyl. The synthesized compounds were tested for in vitro receptor binding, LH release, and stability against chymotrypsin and intestinal degradation. The NMe-Ser4 (30), NMe-Leu7 (33), and Sar10 (35) analogues of nafarelin had pD2 values 2-, 20-, 9-fold higher than their respective parent. All the other N-methyl agonists were less active. For the first time, conversion of LHRH agonists to antagonists was observed as a result of N-methyl substitution in the peptide backbone. [NMe-Phe2,DLeu6,Pro9NHEt]LHRH (4), [NMe-1Nal3,DLeu6,Pro9NHEt]LHRH (6), [NMe-His2,DTrp6,Pro9NHEt]LHRH (14), [NMe-Phe2,DNal6]LHRH (27), and [D2Nal6,NMe-Arg8]LHRH (34) exhibited antagonist responses. Substitutions of NMe-1Nal3, NMe-Ser4, or NMe-Tyr5 in leuprolide rendered the 3-4 peptide bond in these compounds completely stable to chymotrypsin. Examination of the three-dimensional structure of leuprolide when bound to the active site of chymotrypsin, reveals the NH's of residues 3 and 5 are involved in hydrogen bond interactions with the enzyme. N-Methylation at these positions is not only disrupting the hydrogen bond interactions, but is also sterically preventing the substrate from fitting in the enzyme's active site. All the compounds in the leuprolide series were also tested against intestinal degradation using an in vitro rat jejunum sac assay. In this model the pattern of stabilization was similar, but not identical, to that against chymotrypsin. The pharmacokinetics of all the analogues in the leuprolide series and of several others in the deslorelin and nafarelin series were determined. The clearance values of all the three NMe-Tyr5 analogues, 8, 20, and 31 were lower than their respective parents. These slower clearances suggest lower rates of metabolism.

Endometrial response to IVF hormonal manipulation: comparative analysis of menopausal, down regulated and natural cycles.

BACKGROUND: Uterine luminal epithelial cell response to different hormonal strategies was examined to determine commonality when an endometrium attains a receptive, stimulated, morphological profile that may lead to successful implantation. METHODS: Endometrial biopsies from 3 cohorts of patients were compared. The tissue samples taken from these patients were categorized into 8 different groups according to their baseline and the hormone regime used. RESULTS: Pre-treatment natural cycle tissue was variable in appearance. Downregulation with a GnRH analogue tissue appeared menopausal in character. HRT after downregulation resulted in tissue uniformity. HRT in menopause resulted in a 'lush' epithelial surface. HST in the natural cycle improved the morphology with significant difference in secretion between the two regimes examined. CONCLUSIONS: Down regulation plus HRT standardized surface appearance but tissue response is significantly different from the natural cycle, natural cycle plus HRT or menopause plus HRT. HRT in menopause reinstates tissue to a state similar to a natural cycle but significantly different from a natural cycle plus HST. HST with a natural cycle is similar to tissue from the natural cycle but significant differences reflect the influence of the particular hormones present (at any point) within the cycle.

Urinary N-telopeptides to monitor bone resorption while on GnRH agonist therapy.

OBJECTIVES: To assess the utility of urinary cross-linked N-telopeptides in monitoring bone resorption and predicting bone loss during GnRH agonist administration. METHODS: Ninety patients who were prescribed GnRH agonist therapy for 3-6 months for treatment of endometriosis, leiomyomas or other gynecologic disorders participated in this prospective multicenter study. N-telopeptides, serum estradiol (E2), and bone mineral density were monitored before, during and up to 3 months after the course of GnRH agonist therapy. RESULTS: N-telopeptide levels increased significantly throughout GnRH agonist therapy and returned to baseline levels by 3 months after treatment was completed. A significant negative correlation was seen between N-telopeptide and E2 measurements after 3 months (r=-0.23, P<.05), 4 months (r=-0.32, P < .05), and 5 months (r=-0.41, P<.005) of GnRH agonist therapy. The percent change in bone mineral density at L1-L4 at 6 months of GnRH agonist treatment correlated inversely with the percent change in N-telopeptides from baseline to 2,3,4, and 5 months of treatment; the percent change of bone mineral density at the femoral neck at 6 months correlated inversely with the percent change of N-telopeptides from baseline to month 4. CONCLUSIONS: Urinary N-telopeptide determinations provide a quantitative measure of bone resorption, due to GnRH agonist-induced hypoestrogenism. Increases in resorption as measured by N-telopeptides parallel decreases in in E2 levels. Increases in N-telopeptides on GnRH agonist therapy may provide a tool to predict decreases in bone mineral density.

Membrane activity of biotechnological peptide drugs.

Charged Langmuir-Blodgett monolayers deposited at an immobilised liquid-liquid interface have been used as a simple model for a biological membrane to investigate the membrane activity of biotechnological oligopeptide drugs.

Contrasting effects of a gonadotropin-releasing hormone agonist and antagonist on the secretion of free alpha subunit.

Gonadotropin-releasing hormone agonists and antagonists have initial divergent effects on the pituitary secretion of intact biologically active gonadotropins and long-term divergent effects on the secretion of free alpha-subunit. The antagonists appear to function as true competitive inhibitors, blocking the stimulatory effects of endogenous GnRH without evoking any known postreceptor activity. The agonists, in contrast, initially stimulate pituitary secretion and then incompletely desensitize the gonadotrope, resulting in suppression of intact gonadotropin, but not free alpha-subunit, secretion. The mechanisms by which GnRH-a produce this incomplete gonadotrope desensitization and facilitate limited postreceptor activity remain to be elucidated.

Aberrant estradiol flare despite gonadotropin-releasing hormone-agonist-induced suppression is associated with impaired implantation.

Our results confirm the previous report that rapid suppression by GnRH-a is favorable relative to delayed suppression (1). They further indicate that the pattern of E2 production during GnRH-a-induced ovarian suppression may be predictive of cycle outcome. We suggest that imperfect pituitary suppression of bioactive LH as indicated by an aberrant rise in E2 during GnRH-a down-regulation may compromise oocyte quality and ultimately impair implantation. Further study of follicular phase E2 response to GnRH-a suppression may provide a prognostic marker for implantation.

Conservative management for perimenopausal women with uterine leiomyomas using Chinese herbal medicines and synthetic analogs of gonadotropin-releasing hormone.

The effects of a long-term intranasal administration of each of the gonadotropin-releasing hormone analogs, buserelin and nafarelin on uterine leiomyomas after conservative treatment using Chinese herbal medicines, Keishi-bukuryo-gan and Shakuyaku-kanzo-to were investigated in 30 perimenopausal women with leiomyomas. Hypermenorrhea and/or dysmenorrhea as a chief complaint was moderately improved by the treatment using Chinese herbal medicines in more than 60% of the patients with less than fist-sized leiomyomas, but not the over fist-sized. Afterwards, continuous treatment using analogs produced a long-term reduction in leiomyomas (less than 60%) along with decreases in the serum levels of luteinizing hormone, follicle-stimulating hormone, estradiol, and the tumor marker CA-125, and adverse effects including slight boneloss. Long-term treatment using Chinese herbal medicines and gonadotropin-releasing hormone analogs for the management of uterine leiomyomas could be beneficial for patients a few years before menopause, though possible side effects of this treatment should be monitored.

Cytogenetic analysis of uterine leiomyoma: the size, histopathology and GnRHa-response in relation to chromosome karyotype.

OBJECTIVE: The aim of this study was to elucidate the clinical characteristics of uterine leiomyomas having abnormal chromosome karyotype. STUDY DESIGN: A total of 394 myomas were obtained from 213 patients for cytogenetic analysis. The size (number of nodules=144), histopathology (n=302), and gonadotropin-releasing hormone analogue (GnRHa)-response (n=58) were investigated in relation to chromosome karyotype in myomas. RESULTS: 302 myomas from 166 patients were successfully karyotyped. A total of 21 myomas from 21 patients showed abnormal chromosome karyotype. The high frequencies of involved chromosomes 12, 14, 1, 7 were observed. The diameters of myomas with abnormal karyotype were significantly larger than those of myomas with normal karyotype. The frequency of the degeneration in myomas with abnormal karyotype was significantly higher than that with normal karyotype. The reduction rate in size of myomas by GnRHa treatments did not differ between the two types (karyotype normal versus abnormal) of nodules. CONCLUSIONS: Chromosomally abnormal myomas were larger in diameter and showed a higher frequency of degeneration, suggesting that the cytogenetic background in uterine leiomyoma affects a tumor's growth potential.

Impact of six months of GnRH agonist therapy for endometriosis. Is there an age-related effect on bone mineral density?

OBJECTIVE: To determine if there is an age-related effect on bone mineral density (BMD) loss with GnRH agonist treatment of endometriosis and, in particular, whether the impact of this therapy in terms of BMD loss is different if it is used at an age prior to attainment of peak BMD than after attaining it. STUDY DESIGN: Data from a randomized, double-placebo-controlled clinical trial comparing efficacy and safety of two GnRH agonists, without add-back, for the treatment of endometriosis, were analyzed. RESULTS: No significant age-related effect was detected for either GnRH agonist on absolute BMD loss with a single, six-month course. However, in women at an age prior to peak BMD, prevention of the natural increase in BMD with these drugs may prevent women from attaining their peak BMD and thus increase their risk of osteoporosis in later life. CONCLUSION: GnRH agonists should be used with caution and perhaps only with strategies designed to minimize the impact on BMD in women prior to attainment of peak BMD.

Hyalinization and cellular changes in uterine leiomyomata after gonadotropin releasing hormone agonist therapy.

This study evaluated the microscopic changes in leiomyomata following the use of a gonadotropin releasing hormone (GnRH) agonist. Seventeen women with symptomatic leiomyomata were included. Nine were treated with a GnRH agonist for three to six months prior to surgery, and the remaining eight served as controls. Following myomectomy, paraffin sections were prepared from the tumors. These sections were examined microscopically by two gynecologic pathologists, who were blind to the patient groups. The results showed increased cellularity and hyalinization in leiomyomata following GnRH agonist treatment.