Use of a GnRH synthetic analog (buserelin) for estrous induction in female dogs / Utilização de análogo sintético de GnRH (buserelina) na indução do estro em cadelas

The aim of this study was to evaluate the effectiveness of a GnRH synthetic analog, as an estrous inducer in female dogs when administered during the anestrous phase, and to evaluate the pregnancy rate achieved through natural copulation. For this purpose, ten female dogs of different breeds were used. The subjects received buserelin by intramuscular injections at a dose of 2,1mcg when female dogs weighed up to 10kg (Group 1) and of 4,2mcg when the dogs weighed above 10kg (Group 2). Of the ten subjects, only three presented estrus after a single injection of buserelin: two dogs from Group 1 and one dog from Group 2 on average 7±1.29 days. The remaining seven dogs were given a second dose of buserelin, equal to the first administration. Of these, three belonged to Group 1 and four to Group 2. Four of these dogs exhibited clinical signs of estrus within, on average 9±7.3 days from the second injection. The seven female dogs that did enter estrus were fertilized successfully through natural copulation. The administration of buserelin was effective in inducing estrus in female dogs during the anestrous phase, with a maximum of two administrations.(AU)

Objetivou-se avaliar a eficácia de um análogo sintético ao GnRH como indutor de estro em cadelas em anestro e a taxa de prenhez por meio de cópula natural. Para isso, foram utilizadas 10 fêmeas caninas de diferentes raças. Cadelas de até 10kg de peso (grupo 1) foram submetidas à administração de buserelina por via intramuscular, na dose de 2,1mcg, e cadelas acima de 10kg (grupo 2) foram submetidas à mesma medicação, porém na dose de 4,2mcg. Das fêmeas em anestro, apenas três apresentaram estro com apenas uma aplicação, sendo duas do grupo 1 e uma do grupo 2, em 7±1,29 dias, em média. Em sete cadelas foi administrada mais uma dose de buserelina; destas, quatro eram pertencentes ao grupo 2 e três eram do grupo 1. Os sinais de estro ocorreram, em média, após 9±2,73 dias da segunda aplicação. As sete cadelas que manifestaram estro foram fertilizadas por meio de cópula natural. A administração de buserelina é eficiente para a indução de estro, em cadelas em anestro, em, no máximo, duas aplicações.(AU)

S- and C-glycopeptide derivatives of an LH-RH agonist.

The S- and C-glycosylated nonapeptides 1 and 2 were synthesized as analogs of the non-glycosylated LH-RH agonist buserelin (pGlu-His-Trp-Ser-Tyr-D-Ser(tBu)-Leu-Arg-Pro-NHEt) by segment condensation in solution. 1 and 2 differ from this peptide in the amino acid in position 6. In the first case (1), D-serine (tBu) is substituted by D-cysteine carrying a rhamnosyl residue, in the second case (2) D-alanine carrying a galactosyl moiety bound as C-glycoside is incorporated. The bioactivity of both glycopeptides as fertility drugs was determined from the dose dependent LH release in male rats. Additionally, in female rats the ovulation rate was assessed. As a result the analog 1 exhibits a similar biological activity as buserelin while analog 2 shows about 25% of this potency. Compared to buserelin the solubility of the analogs 1 and 2 in aqueous buffer is improved by more than two orders of magnitude due to the carbohydrate moieties.

Novel antitumor peptide hormones and their effect on signal transduction.

A series of novel gonadotropin releasing hormone (GnRH) and Somatostatin analogs have been developed in our laboratory and were screened for antiproliferative and signal transduction inhibitory effect. Our GnRH analog Folligen, had significant antitumor activity on DMBA induced mammary carcinomas in rats without blocking ovarian functions. The direct effect of Folligen and Buserelin has been compared on the human breast cancer cell line MDA-MB-231. Folligen was found to be more effective in inhibiting cell proliferation and significant differences were found in the signal transduction pathways activated by these analogs. Our novel Somatostatin analogs were screened for tyrosine kinase inhibition and for antiproliferative effect on human colon tumor cells and for growth hormone (GH) release inhibition in vitro and in vivo. The analog TT-2-50 was significantly more active inhibiting GH release in superfused rat pituitary cells and in vivo than native Somatostatin and it strongly inhibited tyrosine kinase and proliferation while it stimulated protein kinase C activity.

Aromatization inhibition alone or in combination with GnRH agonists for the treatment of premenopausal breast cancer patients.

Aromatase inhibition in postmenopausal women causes a marked fall in the plasma levels of oestrogens and is an effective treatment for breast cancer, however, trials with aminoglutethimide found that this aromatase inhibitor was ineffective in suppressing plasma oestrogen levels in premenopausal breast cancer patients. We found that the more potent inhibitor, 4-hydroxyandrostenedione (4-OHA), which can suppress oestrogen synthesis in rodents and non-human primates with intact ovarian function, was also unsuccessful as an oestrogen suppressant in premenopausal women at its maximum tolerated dose (500 mg/week i.m.). GnRH agonists are effective suppressants of ovarian oestrogen synthesis but oestrogen production from peripheral sites is unaffected. Our studies of a combination of the GnRH agonist goserelin and 4-OHA demonstrated that the combination caused greater oestrogen suppression than goserelin alone and led to objective clinical response in 4/6 breast cancer patients after their relapse from treatment with goserelin as a single agent. The combination of a GnRH agonist and an aromatase inhibitor should be subjected to clinical trials.

Quantitative estimation of tissue prostate specific antigen, deoxyribonucleic acid ploidy and cytological grade in fine needle aspiration biopsies for prognosis of hormonally treated prostatic carcinoma.

The prognostic value of deoxyribonucleic acid (DNA) flow cytometry, cytological grading and the direct assay of prostate specific antigen (PSA) in the material of fine needle aspirates was studied in 67 consecutive patients with newly detected prostatic carcinoma. All patients were hormonally treated (castration in 27 and luteinizing hormone-releasing hormone agonist or parenteral estrogens in 40). The patients were followed for a minimum of 2 years. PSA was analyzed in the biopsy material by a direct radioimmunoassay and related to the total amount of DNA. In parallel biopsies DNA ploidy using flow cytometry and cytological grade were established. Patients with a geometric mean value of greater than or equal to 0.12 microgram. PSA/microgram. DNA had a progression rate of 7%, compared to 59% for those with less than 0.12 microgram. PSA/microgram. DNA. In Cox multivariate analysis cytology and tissue PSA content were the most important factors in expressing the difference for interval to progression in hormonally treated patients.

Recent developments in endocrine treatment of prostate cancer.

Cancer of the prostate gland is the most frequently occurring malignant lesion in men. Because most prostate cells depend on androgen for growth, removal of testosterone by either orchiectomy or medical castration using diethylstilbestrol or a luteinizing hormone-releasing hormone (LHRH) analogue is first-line treatment for patients with symptomatic Stage D2 disease. The trend in hormonal therapy has been toward long-acting minimal-dosing high-compliance regimens, capitalizing on the recent availability of the long-acting LHRH analogues, which require only monthly injections to maintain castration levels of testosterone, and the nonsteroidal antiandrogen ICI 176,334, which (in early clinical trials) appears to block intracellular testosterone activity with a once-a-day oral regimen. To eliminate the rapid LH increase that can occur during early agonist therapy, combinations of LHRH analogues and antiandrogens (total androgen blockade) have been tested and appear promising. The effects of hormonal treatment in patients with symptomatic Stage D2 prostate cancer have been studied extensively and are relatively well understood. By contrast, hormonal treatment has not been explored in contemporary randomized Phase III trials of asymptomatic Stage D2, D1, or C disease, localized Stage B or A disease, or before prostate surgery or radiation treatment. Research must continue to determine the optimal regimen that suppresses testosterone activity with the least amount of toxicity.

An open randomized comparative study of the effect of goserelin depot and danazol in the treatment of endometriosis. Zoladex Endometriosis Study Team.

OBJECTIVE: To compare the efficacy and safety of goserelin depot and danazol for endometriosis. DESIGN: Open, randomized comparative trial. SETTING: Multicenter European academic clinical institutions. PATIENTS: A total of 307 patients with laparoscopically diagnosed endometriosis were randomized to goserelin (n = 204) or danazol (n = 103); 249 patients underwent second look laparoscopy (175 received goserelin and 74 danazol) and were analyzed for efficacy. INTERVENTIONS: A 3.6-mg depot of goserelin monthly subcutaneously or oral danazol 200 mg three times a day administered for 24 weeks. MAIN OUTCOME MEASURES: Efficacy assessments were based on changes in visible deposits at laparoscopy before and after treatment and subjective symptom scores at 4-week intervals during treatment and 8-week intervals after treatment for up to 24 weeks. Safety was assessed by adverse event reporting and clinical laboratory measures. RESULTS: There were similar proportions of symptomatic (73%) and asymptomatic (but infertile) (27%) and comparable distribution of different severity of endometriosis randomized to each treatment. Significantly fewer patients randomized to goserelin (6.4%) withdrew during treatment compared with 20.4% randomized to danazol (P less than 0.05). There were significantly reduced visible deposits of endometriosis found post-treatment (P less than 0.0001) within each group but no differences between the treatments. The mean total subjective symptoms scores remained significantly less than entry at 24 weeks post-treatment (P less than 0.05). Hypoestrogenic side effects were more common in those receiving goserelin, particularly hot flushes, but anabolic/androgenic side effects of weight gain and muscle cramps were more common in those receiving danazol. CONCLUSIONS: The monthly administered 3.6-mg depot preparation of goserelin was highly effective at inducing resolution of endometriotic implants and relieving the symptoms of endometriosis with prevention of their return during 24 weeks follow-up in the majority of patients. However, results were not significantly different from those achieved with danazol 600 mg/d.

The response of uterine fibroids to GnRH-agonist treatment can be predicted in most cases after one month.

Twenty-seven patients with uterine fibroids were treated for 3 months with the GnRH-agonist goserelin prior to surgical myomectomy. Ovarian function was suppressed reliably in all patients. After three applications, 15 fibroids were reduced in volume by more than 50%, and one complete remission was achieved. Seven patients showed a decrease of 10-50% in volume. However, in 5 cases there was no significant reduction. Analysing the time course of the fibroid reduction, the response can be predicted in most cases as early as four weeks after the first injection. Retrospective statistical analysis showed that a 50% reduction in fibroid size due to GnRH treatment is preceded by a 35% reduction after 4 weeks in 81% of cases, and after 8 weeks in all cases. Only 2 of 12 fibroids, which showed a smaller response (less than 50%) to GnRH therapy, were reduced by more than 35% after 4 and 8 weeks. In most cases it seems to be possible to estimate the individual response to GnRH-application after the first injection, so that it is possible to stop therapy in non-responding patients.

Laparoscopic aspiration of ovarian endometriomas. Effect with postoperative gonadotropin releasing hormone agonist treatment.

In the period 1988-1990 this prospective study of 33 women with moderate or severe endometriosis who underwent laparoscopy for infertility and/or chronic pelvic pain, was conducted to evaluate the efficacy of aspirating endometriotic cysts followed by administration of a gonadotropin releasing hormone (GnRH) agonist in reducing the size of ovarian endometriomas. The cysts (mean diameter, 4.5 cm; range, 2-7; unilateral, 21 cases; bilateral, 12 cases) were punctured, aspirated, washed and emptied completely. After laparoscopy, 15 subjects received goserelin administered as a 28-day subcutaneous depot for three months, whereas 18 patients undergoing simple observation constituted internal controls. Ultrasound scans were performed before and at one, three and six months after laparoscopy. One case and three controls requested surgery between the four- and five-month follow-up scans and did not complete the study. All the other women had recurrent cysts at the six-month scan. There were no significant differences in mean endometrioma diameter between the two groups at any observation time nor between prelaparoscopic and six-month ultrasound examinations within each treatment group. We conclude that aspiration and washing of endometriotic cysts, combined with postoperative administration of GnRH agonists or not, is ineffective.

Antiproliferative effects of luteinizing hormone-releasing hormone agonists on the human prostatic cancer cell line LNCaP.

Highly potent LH-releasing hormone (LHRH) agonists have been recently introduced in therapy for the treatment of the carcinoma of the prostate, an androgen-dependent pathology. These peptides are believed to act mainly by inhibiting the pituitary-testicular axis and, consequently, by reducing testosterone levels. The recent observation that binding sites for LHRH analogs are present on prostatic tumor tissue suggests that these drugs could also act directly on the tumor. To verify this hypothesis, the effects of two potent LHRH agonists [Zoladex (Z) and Buserelin (B)] have been studied on the proliferation of the human prostatic cancer cell line LNCaP (lymph node carcinoma of the prostate). LNCaP cells were treated for 9 days with different doses of either Z or B (concentrations from 10(-12)-10(-6) M). Both analogs significantly inhibited cell proliferation at doses between 10(-9)-10(-6) M. The antiproliferative action of the two LHRH agonists was shown to be dose dependent, with IC50 values of 0.82 and 1.79 nM for Z and B, respectively. A similar treatment with B was without any significant effect on the proliferation of a mouse embryo fibroblast cell line (Swiss 3T3), which was used as a nontumoral control. The inhibitory action of both LHRH agonists (10(-8) M) on LNCaP cell proliferation was completely antagonized by the simultaneous treatment of the cells with a potent LHRH antagonist (Nal-Arg-LHRH; 10(-8) M); when given alone at the dose selected, the antagonist did not affect cell growth. These results clearly suggest that the antiproliferative effect of LHRH agonists on LNCaP cells may be mediated by specific receptors. The presence of binding sites for [125I]B was consequently demonstrated on the membranes of LNCaP cells cultured in a medium containing charcoal-stripped fetal calf serum, i.e. in the absence of steroids. The affinity of these binding sites for the ligand was lower than that observed for the same receptors on rat pituitary membranes. To clarify the mechanism of the antiproliferative action of the LHRH agonists, the effects of both Z and B on the incorporation of [3H]thymidine and [14C]methionine into LNCaP cells were investigated. During a short incubation period (3 h), the two LHRH agonists rapidly inhibited [3H]thymidine incorporation into the cells. The same treatment did not affect the incorporation of [14C]methionine into proteins.(ABSTRACT TRUNCATED AT 400 WORDS)

Response to second-line hormonal manipulation monitored by serum PSA in stage D2 prostate carcinoma.

Changes in prostate-specific antigen (PSA) have been demonstrated to accurately assess response to initial hormone deprivation in metastatic prostate cancer patients. The role of PSA in monitoring response to second-line hormonal treatment has not been documented. In a group of 20 patients with an initial response to androgen deprivation and subsequent relapse, we monitored PSA levels before and after second-line therapy. Ten patients had a clinical response. Four had a more than 90 percent decrease in serum PSA compared with the level at initial progression. This clinical response was maintained for a mean of eighteen months. Six patients had a PSA decrease less than 90 percent; their clinical response was of a mean 5.5 months. Ten patients had no change or increase in PSA. Seven had no clinical response, and 3 responded for an average of four months. Although production of PSA might be under endocrine control, changes in PSA are useful for monitoring response to second-line hormonal therapy.

Gonadotropin releasing hormone agonist treatment for severe menorrhagia in patients with contraindications to surgery.

Four patients with heavy menorrhagia, severe iron-deficiency anemia and contraindications to surgery were treated with a gonadotropin-releasing hormone agonist in a depot formulation. At 2 months of therapy they were all amenorrheic, and at 6 months the hematologic values had improved markedly. Gonadotropin-releasing hormone agonists may obviate emergency surgery in patients at high surgical risk or could constitute the first line of sequential therapeutic regimens, once general health conditions have improved.

Management of fibroids.

This review covers literature published between December 1990 and November 1991. It shows a continuous outpouring of publications on the use of gonadotropin-releasing hormone agonists and operative hysteroscopy as part of the background of alternatives to hysterectomy. The new technologies question traditional management of fibroids, which may vary considerably in different areas. Abdominal myomectomy, which never received adequate recognition as an alternative in the past, is also discussed. The review concludes with a section on abdominal hysterectomy.

Goserelin (Zoladex) depot in the treatment of endometriosis. Zoladex Endometriosis Study Group.

STUDY OBJECTIVE: To evaluate the safety and efficacy of Goserelin (Zoladex depot; ICI Pharmaceuticals, Macclesfield, Cheshire, United Kingdom) in the treatment of endometriosis. DESIGN: Open study. SETTING: Eleven centers in Germany and 1 center in Austria. PATIENTS: One hundred forty-six patients with pelvic endometriosis. INTERVENTION: Goserelin (Zoladex depot) therapy, one depot (3.6 mg) subcutaneously every 4 weeks for 6 months. RESULTS: Total subjective score and total pelvic symptom score showed a reduction by 86% and 93%, respectively, at the end of the treatment and did not exceed one fifth of the pretreatment value throughout the follow-up period of 48 weeks. One hundred seven women underwent a second laparoscopy at the end of the therapy for determination of objective efficacy: 54% of the patients showed a reduction of implants and adhesions by at least 50% or more, and 31.5% had a complete resolution of visible deposits. The mean reduction of implants and adhesions was 50%, and the mean reduction of implants 72%. Twenty of 64 (31.3%) previously infertile patients successfully conceived within 12 months after discontinuation of the therapy. Goserelin led to a down regulation of the pituitary ovarian axis and as a pharmacological effect of this hypoestrogenism most patients had hot flushes and vaginal dryness. CONCLUSIONS: Zoladex depot therapy proved to be safe and effective in the medical treatment of endometriosis.

Hormonal treatment of unresectable pancreatic cancer with LHRH analogue (goserelin).

Recently non-controlled clinical trials reported encouraging results using a suppressive endocrine treatment in patients with unresectable pancreatic cancer. In this study 15 patients were given an LHRH analogue every 4 weeks (goserelin 3.6 mg), while 18 patients with advanced stage pancreatic carcinoma were given only symptomatic therapy. All patients treated with goserelin had sexual hormone suppression. Follow-up included abdominal ultrasound or computed tomography scan every 3 months; Ca 19-9 assay and routine laboratory blood tests were performed every month. No partial or complete response, no performance status or Ca 19-9 level changes were found. No significant difference in survival was seen in the two groups of patients. This study suggests that goserelin is unlikely to have a major influence on the survival of patients with advanced pancreatic carcinoma and casts further doubt upon the hormone-dependence of this neoplasm.

Phase III randomised study of zoladex versus stilboestrol in the treatment of advanced prostate cancer.

An open randomised Phase III trial was conducted of the depot GnRH analogue goserelin (Zoladex) versus stilboestrol (3 mg/day) in patients with advanced or metastatic prostate cancer. The study included 250 patients and the median follow-up was 43 months. In the Zoladex arm the time to first response was achieved earlier and more patients reported an improvement in symptoms. There was no statistically significant difference between the Zoladex and the stilboestrol arms with regard to survival and time to treatment failure. A major reason for treatment failure was the preponderance of adverse events in patients receiving stilboestrol. It is suggested that stilboestrol should no longer be used for prostate cancer when equally effective alternative treatments are available.

Effects of the gonadotrophin-releasing hormone agonist 'Zoladex' upon pituitary and gonadal function in hypogonadal (hpg) male mice: a comparison with normal male and testicular feminized (tfm) mice.

Hypogonadal (hpg) mutant mice, with a congenital deficiency of hypothalamic gonadotrophin-releasing hormone (GnRH), and testicular feminized (tfm) mice, which lack a functional androgen receptor, were used to study the effects of the potent GnRH agonist 'Zoladex' (ICI 118630; D-Ser (Bu(t))6, Azgly10-GnRH) on pituitary and gonadal function. Zoladex (0.5 mg) in a sustained-release lactide-glycolide copolymer depot was administered subcutaneously under anaesthesia and was left in place for 7 days, after which time the effects of the drug upon pituitary and serum gonadotrophin concentrations, glycoprotein hormone subunit mRNAs and testicular morphology were investigated. At the pituitary level, Zoladex treatment resulted in a substantial reduction in LH content in normal males, and LH content was depressed in hpg mice even below the basal levels normally found in these mutants. Pituitary LH content in the Zoladex-treated animals was depressed in the tfm groups, but not to the same levels as those found in the normal and castrated normal mice. Zoladex treatment at the time of castration prevented the post-operative elevation in serum LH associated with castration alone. In the androgen-deficient tfm mouse, Zoladex did not depress the normally elevated serum LH levels. Serum LH in the hpg animals was, in all cases, below the limit of detection of the assay. Pituitary FSH content was depressed into the hpg range in both the normal and castrated animals, but there was no further depression in the hpg mice. The pituitary content was reduced in the tfm mice, again the effects not being as dramatic as in the normal and castrated animals. Serum FSH content, as measured by radioimmunoassay, was depressed by 50% in normal mice; there was no reduction in the hpg mice, however. With regard to pituitary gonadotrophic hormone gene expression, Zoladex administration to normal mice caused a dramatic reduction in LH beta mRNA content, to a level approximating that found in untreated hpg mice. The drug also depressed LH beta mRNA in the castrated group to the hpg range when given at the time of castration, whereas in untreated castrated mice there was a significant increase in LH beta mRNA. In the tfm mouse, which can be considered as a model for long-term failure of androgen feedback, Zoladex again induced a fall in LH beta mRNA, but not to the same extent as in the normal and normal castrated group. Zoladex had no effect on the already low levels of LH beta mRNA found in hpg mice.(ABSTRACT TRUNCATED AT 400 WORDS)

Hormonal cytoreduction and radiotherapy for carcinoma of the prostate.

We report the effect on prostatic volume of the administration of the luteinising hormone-releasing hormone (LHRH) analogue goserelin in 22 patients with locally advanced carcinoma of the prostate; 20 achieved a significant reduction in volume, the median volume being 66 ml before treatment (range 40-130) and 30 ml after 17 weeks (range 13-47). If used before external beam radiotherapy (RT), volume reduction will permit smaller boost fields and thus potentially reduce adverse radiotherapy effects. In addition, reducing tumour volume before RT may lead to an increase in local control. We discuss the possible role of hormonal volume reduction in the management of prostatic cancer.

Comparison of two oestrogen receptor assays in the prediction of the clinical course of patients with advanced breast cancer.

We have examined two new oestrogen receptor (ER) assays--an enzyme immunoassay (EIA) and an immunocytochemical assay (ICA) in a large series of primary breast tumours to compare their potential as predictors of (1) response to endocrine therapy and (2) survival in patients developing advanced breast cancer. Response to endocrine therapy was categorised at 6 months (UICC criteria). ER-ICA appears the better predictor of response to endocrine therapy than ER-EIA. Combining ICA and EIA results did not improve the prediction of response. With both assays patients with ER positive tumours survived longer from the time of diagnosis of advanced disease than those with ER negative tumours. The predictive power of these assay for progression of disease appears slightly better for the ER-ICA.