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PubMed1991

Intranasal buserelin versus surgery in the treatment of uterine leiomyomata: long-term follow-up.

Forty-two women with symptomatic uterine myomas, candidates for myomectomy or hysterectomy, were randomized to 6 months' treatment with buserelin 1200 micrograms/day intranasally (n = 22) or immediate surgery (n = 20). After buserelin treatment or operation the patients were followed for at least 12 months. Buserelin was well tolerated, the uterine volume fell from 465 +/- 168 to 273 +/- 88 cm3, and hemoglobin values normalized in all anemic patients. Rapid myoma regrowth was observed in all patients in the buserelin group after treatment withdrawal. Pregnancy occurred during follow-up in one of five buserelin-treated myomectomy candidates. Menorrhagia recurred in eight of 15 buserelin-treated hysterectomy candidates, and a hysterectomy was required but no transfusion was needed. Two women entered natural menopause and were considered cured. In the surgery group all operations were uneventful: three women conceived after myomectomy, whereas four of the patients that underwent hysterectomy required transfusions. Thus buserelin treatment appears to be indicated for infertile patients when surgery is contra-indicated or could cause adhesions, and for hysterectomy candidates in perimenopausal age and/or with secondary anemia.

Administration, Intranasal↗
PubMed1992

Tamoxifen in the rat prevents estrogen-deficiency bone loss elicited with the LHRH agonist buserelin.

In young women chronic use of luteinizing hormone releasing hormone (LHRH) agonists such as buserelin to treat endometriosis leads to estrogen-deficiency bone loss. Tamoxifen citrate is an estrogen agonist/antagonist which protects the skeleton from osteopenia when ovarian hormones are depleted. The present study was undertaken to determine whether tamoxifen citrate (20 mg/kg body wt/week s.c.) could prevent the osteopenic effect of buserelin (25 micrograms/kg body wt/day s.c.). Four groups of rats with 45Ca-labelled bones were studied for 4 weeks: group A--placebo controls; group B--buserelin; Group C--tamoxifen; group D--buserelin+tamoxifen. Bone resorption was monitored by measuring the urinary excretion of 45Ca and hydroxyproline. Interestingly buserelin lowered both blood 17 beta-estradiol values and uterine weights in the presence and absence of tamoxifen. However, tamoxifen slowed bone breakdown and inhibited the bone-thinning effects of buserelin. Total body calcium values (mg; means +/- S.D.) were: 2227 +/- 137; 1926 +/- 124; 2233 +/- 94 and 2268 +/- 163, in groups A to D respectively. Osteopenia was thus present only in group B (P less than 0.001). Because tamoxifen inhibits estrogen-deficiency bone loss in buserelin-treated rats without depressing the hypoestrogenic actions of this LHRH-agonist, we suggest that use of tamoxifen to protect the skeleton during LHRH-agonist therapy in young women should be explored. Tamoxifen citrate might also help to prevent postmenopausal osteoporosis.

Animals↗
PubMed2001

A prospective randomized comparison of routine buserelin acetate and a decreasing dosage of nafarelin acetate with a low-dose gonadotropin-releasing hormone agonist protocol for in vitro fertilization and intracytoplasmic sperm injection.

OBJECTIVE: To compare the efficacy of a draw-back nafarelin acetate protocol with routine buserelin acetate administration for in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). DESIGN: Prospective clinical study. SETTING: Mie University School of Medicine, Tsu, Mie, Japan. PATIENT(S): One hundred sixty-nine women treated with IVF and 183 women treated with ICSI. INTERVENTION(S): Nafarelin acetate and buserelin acetate in ovarian hyperstimulation in IVF and ICSI were administered. MAIN OUTCOME MEASURE(S): The concentrations of estradiol (E(2)), FSH, LH, gonadotropin dosages; the number of oocytes retrieved, oocytes fertilized, and embryos; and pregnancy rates. RESULT(S): A prospective study was conducted with 44 cycles for 34 couples with nafarelin acetate (group 1) and 47 cycles for 40 couples with buserelin acetate (group 2) with a long IVF protocol; 68 cycles for 46 couples with nafarelin acetate (group 3) and 56 cycles for 39 couples with buserelin acetate (group 4) with a short IVF protocol; 39 cycles for 32 couples with nafarelin acetate (group 5) and 50 cycles for 30 couples with buserelin acetate (group 6) with a long ICSI protocol; and 87 cycles for 60 couples with nafarelin acetate (group 7) and 81 cycles for 61 couples with buserelin acetate (group 8) with a short ICSI protocol. Patients were randomized to receive either full-dose nafarelin acetate (200 microg b.i.d.) treatment for 7 days followed by half-dose nafarelin acetate (200 microg daily) or buserelin acetate (300 microg t.i.d.). There were no statistically significant differences in baseline concentrations of E(2) and FSH, concentrations of E(2), P4, FSH, LH on hCG administration, gonadotropin dosage, the number of oocytes retrieved and embryos transferred, or pregnancy rates between groups 1 and 2, groups 3 and 4, groups 5 and 6, and groups 7 and 8. CONCLUSION(S): Full-dose nafarelin acetate treatment for 7 days followed by half-dose nafarelin acetate ("draw-back" protocol) is an effective new protocol for IVF and ICSI.

Abortion, Spontaneous↗
PubMed2002

In vivo modulation of follicle-stimulating hormone release and beta subunit gene expression by activin A and the GnRH agonist buserelin in female rats.

The effects of separate and simultaneous recombinant bovine (rb) activin A and buserelin administration on the FSH release and pituitary FSH beta subunit gene expression in vivo were examined in ovariectomised, estradiol pretreated rats. The animals received a single injection of either rb activin A (50 ng), buserelin (1 micro g) or activin/buserelin (50 ng+1 micro g/0.1 ml PBS) into the jugular vein and were killed 30 min, 1, 3 and 5h later. Activin A stimulated FSH release and effect appeared 1h after injection (168% increase of controls) reaching a maximum at 3h (437% of controls). Activin A and buserelin exerted their effects with a distinct time courses: activin's stimulation was not so rapid when compared with buserelin. The simultaneous administration of rb activin A and buserelin amplified FSH release (118, 309, 1006 and 779% of controls). The low dose of activin A was sufficient to elevate FSH beta mRNA level as early as 3 and 5h after administration (170 and 140%, respectively). Activin plus buserelin stimulation resulted in a higher (340 and 360% of controls) FSH beta gene expression than after their separate administration. These results suggest that activin and buserelin may act independently and synergistically in the regulation of FSH release and beta subunit mRNA level.

Activins↗
PubMed1989

A controlled study of luteinizing hormone-releasing hormone agonist (buserelin) for the induction of folliculogenesis before in vitro fertilization.

Treatment with clomiphene citrate and human menopausal gonadotropin (HMG) is often used to induce folliculogenesis before in vitro fertilization, but not all women have an adequate response. It has been hypothesized that abnormally high levels of luteinizing hormone (LH) may contribute to the reduced folliculogenesis. We therefore performed a controlled, open trial in which treatment with buserelin, an agonist of luteinizing hormone-releasing hormone citrate and HMG in 44 consecutive women in whom no oocytes or only one had been produced by standard treatment with clomiphene and HMG. Twenty-nine women received buserelin with HMG, and 15 received clomiphene citrate with HMG. The median number of oocytes per patient recovered from those who received buserelin with HMG was 4 (range, 0 to 19), as compared with 0 (range, 0 to 5) in those who received clomiphene citrate with HMG. The fertilization rates of oocytes recovered from both groups of patients were similar (75.8 percent and 76.5 percent, respectively). Fifty-four percent of patients given buserelin with HMG underwent triple-embryo transfer, as compared with 13 percent of those given clomiphene citrate with HMG. Pregnancy (n = 3) occurred only among the patients receiving buserelin with HMG. In the buserelin-HMG group, significantly fewer oocytes were recovered from patients with occult ovarian failure (infertility and elevated follicular-phase levels of follicle-stimulating hormone, with regular menses) (median, 1; range, 0 to 4) than from those with other causes of infertility (median, 8; range, 0 to 19). Our data suggest that, except in women with occult ovarian failure, buserelin and HMG improve embryologic and clinical outcomes in patients with previously unsatisfactory stimulation of the ovaries for in vitro fertilization.

Administration, Intranasal↗
PubMed1995

A prospective randomized single-blind comparative trial of nafarelin acetate with buserelin in long-protocol gonadotrophin-releasing hormone analogue controlled in-vitro fertilization cycles.

The use of gonadotrophin-releasing hormone (GnRH) agonists to control ovulation induction cycles for in-vitro fertilization (IVF) has been shown to increase the pregnancy rate and live birth rate compared with non-analogue cycles. Different formulations of GnRH agonist are available with different routes and frequencies of administration. In this prospective study, the efficacy and safety of intranasal nafarelin and buserelin as adjunctive therapy during IVF were assessed. A total of 240 female patients were recruited to the study and in the first phase patients were randomized to receive either intranasal nafarelin 200 micrograms twice daily or buserelin 200 micrograms five times daily. In the second phase, patients received either nafarelin 400 micrograms twice daily or buserelin 200 micrograms five times daily. Nafarelin 400 micrograms and buserelin 200 micrograms both produced clinical pregnancy rates of 31% per recruit and 39% per embryo transfer. The rates for nafarelin 200 micrograms were 23 and 37% respectively. There was no statistically significant difference in pregnancy rates, by either drug or dosage. The time taken for pituitary down-regulation to be achieved was significantly longer on nafarelin 200 micrograms than on either nafarelin 400 micrograms or buserelin. The total number of days stimulation with human menopausal gonadotrophin required to reach criteria for human chorionic gonadotrophin (HCG) administration was significantly longer on buserelin than on either dose of nafarelin. Median serum oestradiol concentrations on the day of HCG administration were significantly higher on either dose of nafarelin than on buserelin.

Administration, Intranasal↗
PubMed1993

Subcutaneous goserelin versus intranasal buserelin for pituitary down-regulation in patients undergoing IVF: a randomized comparative study.

One-hundred women undergoing ovarian stimulation with gonadotrophin-releasing hormone agonist (GnRH-a) and a human menopausal gonadotrophin (HMG) for in-vitro fertilization (IVF) participated in this randomized comparative study. The effectiveness of long-acting s.c. goserelin (Zoladex depot; 49 patients) and intranasally (i.n.) administered buserelin acetate (Suprefact; 51 patients) for pituitary down-regulation was compared. Treatment with s.c. goserelin (3.6 mg) or i.n. buserelin acetate (200 micrograms; 6 times/day) was started on day 21-23 of the cycle. Stimulation with 150 IU of HMG/day was started after at least 11 days of GnRH-a treatment. There were no differences in the time required for follicular development nor in the clinical outcome between groups treated with either goserelin or buserelin. The number of oocytes recovered in the goserelin group was 6.7 +/- 5.0 versus 6.3 +/- 4.9 in the buserelin group. There were 11 pregnancies after the use of goserelin (22.4%) and 12 pregnancies in those given buserelin (24.0%). The number of HMG ampoules needed for follicular maturation was higher in the goserelin group (27.9 +/- 7.8) than in the buserelin group (24.6 +/- 7.8, P < 0.05). The patients given buserelin suffered significantly more from tiredness, depression, headache and abdominal pain than those receiving goserelin, whereas there were no differences between the groups in experiencing mental irritability, nausea and swelling. Subcutaneous goserelin depot injection offers a useful alternative for pituitary down-regulation in IVF stimulation.

Administration, Intranasal↗
PubMed1988

A randomized, comparative study of buserelin with DES/orchiectomy in the treatment of stage D2 prostatic cancer patients.

This multicenter, randomized study compared the LH-RH agonist buserelin with diethylstilbestrol (DES)/orchiectomy in the treatment of patients with stage D2 prostatic carcinoma. Subjects were randomized to treatment with buserelin or DES/orchiectomy in a 2:1 ratio. Data from 160 subjects were available for analysis: 105 buserelin subjects (89 s.c. and 16 i.n.), 41 DES-treated subjects, and 14 orchiectomized subjects. Either subcutaneous (200 micrograms q.d.) or intranasal (400 micrograms t.i.d.) maintenance doses of buserelin suppressed serum testosterone values to below castrate levels (less than 100 ng/dl) by week 3 and maintained suppression for over 24 months. Times to treatment failure for specific reasons were analyzed and compared between treatment groups. There was a significant difference between treatment groups in favor of buserelin in the time to treatment failure due to an adverse event (p less than or equal to 0.05). There were no statistically significant differences between the treatment groups in the progression-free survival, best response, and life survival analyses. In addition, buserelin treatment improved quality of life parameters such as pain, performance status, and genitourinary symptoms. With the exception of symptoms of androgen deficiency, few side effects were reported in the buserelin subjects and most were of a minor nature. The incidence of severe side effects was significantly higher among the DES/orchiectomy subjects.

Administration, Intranasal↗
PubMed1986

[Inhibitory effect of prolactin secretion by luteinizing hormone releasing hormone agonist (buserelin)].

The LH RH agonist Buserelin was continuously administered through the nose over an extended period to 5 patients with endometriosis at daily doses ranging between 300 micrograms and 1,200 micrograms. The clinical findings and endocrinological dynamics, with emphasis on PRL secretion function, were investigated and the findings below were obtained. The clinical findings showed Buserelin to be effective against endometriosis. The administration of Buserelin markedly inhibited the secretion of LH and FSH under LH-RH loading. The administration of Buserelin markedly inhibited the secretion of PRL and the degree of inhibition appeared to be dependent on the dose and duration of Buserelin administration. No correlation between E2 and PRL was observed during Buserelin administration. The findings suggest that Buserelin inhibits PRL secretion by direct CNS activity, not indirectly through inhibition of E2 production.

Administration, Intranasal↗
PubMed1992

Buserelin treatment of cryptorchidism: a randomized, double-blind, placebo-controlled study.

The objectives of the study were to determine whether a low dose of a luteinizing hormone-releasing hormone analogue (buserelin) has an effect on testicular descent, if buserelin affects germ cell maturation and epididymal development, the incidence of retractile testes in the controlled trials, and if the subsequent administration of human chorionic gonadotropin has any effect on the groups treated. The study was double blind, placebo controlled in which patients with cryptorchidism were assigned randomly into 3 groups: buserelin treatment (22), surgical treatment (18) or placebo control group (19). The 3 groups of patients were similar before treatment in regard to testicular position, chronological and bone age, height and weight, luteinizing hormone, follicle-stimulating hormone, testosterone, penile size and the volume of the contralateral testis. Buserelin (20 micrograms). administered daily in a nasal spray significantly induced testicular descent compared to the group treated with a placebo (p less than 0.01). A normal epididymis was found more often in boys with successful descent (p less than 0.003). Boys treated with buserelin had the highest number and the best maturation index of the germ cells; human chorionic gonadotropin influenced the descent in both groups but it was more efficacious when it was administered after treatment with buserelin, although it had no additional effect on germ cell maturation. None of the boys had retractile testes. Buserelin was capable of inducing testicular descent in addition to increasing simultaneously the number of germ cells and provoking further development of the epididymis.

Child↗
PubMed2001

Comparison of oestrus synchronisation programmes in dairy cattle using oestradiol benzoate, short-acting progesterone and cloprostenol, or buserelin and cloprostenol.

AIM: To evaluate the efficacy of a programme using oestradiol benzoate, progesterone and the prostaglandin-F2 (PG) analogue, cloprostenol, to synchronise oestrus and ovulation in dairy cows, compared with a programme using a gonadotropinreleasing hormone (GnRH) agonist, buserelin, and cloprostenol. METHODS: Twenty non-lactating dairy cows, at random stages of the oestrus cycle, were randomly assigned to 1 of 2 treatments. In Treatment 1 ( OPPG; n=10), cows were injected with 2 mg oestradiol benzoate intramuscularly (IM) plus 200 mg progesterone subcutaneously (SC) on Day 0, followed by 500 microg cloprostenol IM on Day 9 and 1 mg oestradiol benzoate on Day 10. In Treatment 2 (GPG; n=10), cows were injected with 10 microg buserelin IM on Day 0, 500 microg cloprostenol IM on Day 7 and 10 microg buserelin on Day 9. The ovaries of all cows were examined by ultrasonography, using an 8 MHz probe, from 5 days before the initial treatment until ovulation. Cows were observed for oestrus 3 times daily for 7 days after cloprostenol treatment. Blood samples were collected daily for determination of progesterone, and 6-hourly for 36 h after the second oestradiol or buserelin injection for the determination of follicle stimulating hormone (FSH) and luteinising hormone (LH) concentrations. RESULTS: The percentage of cows observed in oestrus was higher in the OPPG group than in the GPG group (100% vs 55.6%, p=0.018). Treatment with either short-acting progesterone plus oestradiol benzoate or buserelin was followed by atresia or ovulation of the dominant follicle. Emergence of a new follicular wave occurred earlier (p>0.001) in the GPG group (2.2+/-0.2 days) than in the OPPG group (3.6+/-0.2 days). There was no significant difference between treatment groups in the variation of time of follicular wave emergence or size of the largest follicles at either the time of initial treatment (10.8+/-1.4 mm vs 11.1+/-0.8 mm), cloprostenol treatment (13.8+/-0.7 mm vs 14.0+/-1.3 mm) or of ovulation (15.4+/-0.7 mm vs 17.6+/-1.1 mm; p=0.10). The LH surge occurred sooner after the second injection of buserelin (4.0+/-1.0 h) than after the second injection of oestradiol benzoate (22.8+/-1.2 h; p>0.001). The interval between the second injection of oestradiol benzoate or buserelin and ovulation did not differ significantly between treatment groups (1.7+/-0.3 days vs 1.6+/-0.2 days; p=0.69). CONCLUSIONS: The use of short-term progesterone treatment, combined with oestradiol benzoate for follicular wave synchronisation, and cloprostenol to cause lysis of residual luteal tissue, is a promising alternative to established methods of oestrus synchronisation in cows.

Journal Article↗
PubMed1995

Improvement of nasal bioavailability of luteinizing hormone-releasing hormone agonist, buserelin, by cyclodextrin derivatives in rats.

The effects of chemically modified cyclodextrins on the nasal absorption of buserelin, an agonist of luteinizing hormone-releasing hormone, were investigated in anesthetized rats. Of the cyclodextrins tested, dimethyl-beta-cyclodextrin (DM-beta-CyD) was the most effective in improving the rate and extent of the nasal bioavailability of buserelin. Fluorescence spectroscopic studies indicated that the cyclodextrins formed inclusion complexes with buserelin, which may reduce the diffusibility of buserelin across the nasal epithelium and may participate in the protection of the peptide against enzymatic degradation in the nasal mucosa. Additionally, the cyclodextrins increased the permeability of the nasal mucosa, which was the primary determinant based on the multiple regression analysis of the nasal absorption enhancement of buserelin. Scanning electron microscopic observations revealed that DM-beta-CyD induced no remarkable changes in the surface morphology of the nasal mucosa at a minimal concentration necessary to achieve substantial absorption enhancement. The present results suggest that DM-beta-CyD could improve the nasal bioavailability of buserelin and is well-tolerated by the nasal mucosa of the rat.

Absorption↗
PubMed2001

GnRH agonist Buserelin affects colony-forming efficiency of HHUA and Jurkat cells.

In this study, cell proliferation was examined at low and high cell densities, using HHUA and Jurkat cell lines as experimental models for the antiproliferative and proliferation-enhancing effects of GnRH agonist, Buserelin, respectively. For efficient evaluation of Buserelin activity at low cell density, the colony-forming efficiency assay was adopted. Buserelin markedly affected colony-forming efficiency in a dose-dependent manner at low cell density; however, Buserelin had no effect at high cell density. The conditioned medium of HHUA cells inhibited the Buserelin action, whereas that of Jurkat cells mimicked it. These results suggest that each cell line secretes some substances which regulate cell proliferation, and that these substances can also change the effects of Buserelin. The measurement of colony-forming efficiency is a very effective way of eliminating autocrine and/or paracrine effects, and is a highly sensitive method for measuring GnRH activity.

Animals↗
PubMedDate not supplied

Disposition of 3H-labelled buserelin continuously infused into rats.

The disposition of the gonadotropin-releasing hormone (GnRH) agonist buserelin was studied in male rats under conditions of long-term administration. Rats were continuously infused with about 30 pmole [3H]-buserelin/24 h subcutaneously by osmotic minipumps for 4-7 days. After killing the rats, the 3H-activity of the tissues was measured and was found to be highly concentrated (about 10-fold to plasma) only in the pituitary. The daily amounts of 3H-activity excreted in urine and faces were constant over the whole infusion period, suggesting steady state conditions. On a molar basis, of the infused dose of buserelin, 14.8% was found to be excreted into urine as intact peptide, and 16.5, 10.8 and 20.6% as the partial buserelin sequences 1-2, 1-3 and 5-9. It is concluded that the major elimination route of buserelin, constant with time, is glomerular filtration, followed by enzymatic degradation of part of the filtered peptide by kidney tubuli enzymes to the partial sequences 1-2, 1-3 and 5-9, which reflects the proteolytic breakdown of buserelin by kidney membrane peptidases in vitro. Based on the similarities in the pharmacokinetics, in vivo metabolities, and in vitro enzymatic degradabilities among the GnRH agonists that have the native GnRH sequence modified at position 6 with or without additional modification at the C-terminal, the elimination process as shown here for buserelin should also be valid for other GnRH agonists.

Animals↗
PubMed1984

Comparison between the biological effects of LH-RH and buserelin on the induction of LH release from hemi-pituitary glands of female rats in vitro.

The biological effects of LH-RH and the agonist [D-Ser(But)6-des Gly10]-LH-RH(1-9)-ethylamide (buserelin) were compared during 8 h of incubation with female rat hemi-pituitary glands. Similar dose-response relationships were found for LH-RH and buserelin as concerns the release of luteinizing hormone (LH) by pituitary glands from intact and ovariectomized rats. Also the LH secretion patterns from glands of intact rats were similar: an initial low response was followed by a fast increase (priming effect) after which the response declined again (desensitization). In a subsequent experiment pituitary glands from ovariectomized rats were first exposed to LH-RH or buserelin for 4 h and then further incubated in medium only. After discontinuation of the stimuli the rate of LH release decreased in all cases, but this decrease was significantly greater when the glands had been exposed to LH-RH. Short-term (1/2, 1 or 2 h) exposures to LH-RH or buserelin followed by an intervening period (1 1/2, 1 or 0 h, respectively) of incubation in medium only resulted in an almost similar, significant increase in the subsequent protein synthesis-independent LH response to LH-RH (priming effect). Only preincubation with LH-RH for 2 h was significantly more effective. The results demonstrate equal intrinsic activities for LH-RH and buserelin. Differences in the biopotencies for LH-RH and buserelin in vivo and in vitro may occur only after discontinuation of the external stimuli.

Animals↗
PubMed1991

17 beta-estradiol protects rats from osteopenia associated with administration of the luteinising hormone releasing hormone (LHRH) agonist, buserelin.

Bone loss associated with sustained administration of luteinising hormone releasing hormone (LHRH) agonists, such as buserelin, is attributed to estrogen deficiency. However, the possibility that the LHRH agonists themselves may contribute to the pathogenesis of bone thinning, has not been ruled out. The aim of the present study was to determine whether or not oral 17 beta-estradiol (300 micrograms/kg body wt/week) would fully prevent the osteopenic effect of buserelin (25 micrograms/kg body wt/day s.c.) in the rat. Four groups of animals with 45Ca-labelled skeletons were studied for 4 weeks: group 1, placebo controls; group 2, 17 beta-estradiol; group 3, buserelin; group 4, 17 beta-estradiol + buserelin. Buserelin alone lowered blood estradiol concentrations, increased bone resorption and reduced femur and total body calcium and 45Ca values. Total body calcium values (means +/- SD) were: (mg) 3405 +/- 176; 3250 +/- 282; 2813 +/- 133; 3156 +/- 452 in groups 1 to 4, respectively. Significant osteopenia was present only in group 3 (P less than 0.001). These results support the view that buserelin-mediated bone loss is due to estrogen deficiency. They do not indicate that LHRH agonists per se, play any role in causing bone thinning.

Animals↗
PubMed1998

Effects of buserelin injection and deslorelin (GnRH-agonist) implants on plasma progesterone, LH, accessory CL formation, follicle and corpus luteum dynamics in Holstein cows.

The influence of Buserelin injection and Deslorelin (a GnRH analogue) implants administered on Day 5 of the estrous cycle on plasma concentrations of LH and progesterone (P4), accessory CL formation, and follicle and CL dynamics was examined in nonlactating Holstein cows. On Day 5 (Day 1 = ovulation) following a synchronized estrus, 24 cows were assigned randomly (n = 4 per group) to receive 2 mL saline, i.m. (control), 8 micrograms, i.m. Buserelin or a subcutaneous Deslorelin (DES) implant in concentrations of 75 micrograms, 150 micrograms, 700 micrograms or 2100 micrograms. Blood samples were collected (for LH assay) at 30-min intervals for 2 h before and 12 h after GnRH-treatment from cows assigned to Buserelin, DES-700 micrograms and DES-2100 micrograms treatments and thereafter at 4-h intervals for 48 h. Beginning 24 h after treatment, ovaries were examined by ultrasound at 2-h intervals until ovulation was confirmed. Thereafter, ultrasonography and blood sampling (for P4 assay) was performed daily until a spontaneous ovulation before Day 45. A greater release of LH occurred in response to Deslorelin implants than to Buserelin injection (P < 0.01). Basal levels of LH between 12 and 48 h were higher in DES-700 micrograms group than in DES-2100 micrograms and Buserelin (P < 0.05). The first wave dominant follicle ovulated in all cows following GnRH treatment. Days to CL regression did not differ between treatments, but return to estrus was delayed (44.2 vs 27.2 d; P < 0.01) in cows of DES-2100 micrograms group. All GnRH treatments elevated plasma P4 concentrations, and the highest P4 responses were observed in the DES-700 micrograms and DES-2100 micrograms groups. The second follicular wave emerged earlier in GnRH-treated than in control cows (9.9 vs 12.8 d; P < 0.01). However, emergence of the third dominant follicle was delayed in cows of DES-2100 micrograms treatment (37.0 d) compared with DES-700 micrograms (22.2 d), Buserelin (17.8 d) or control (19.0 d). In conclusion, Deslorelin implants of 700 micrograms increased plasma P4 and LH concentrations and slightly delayed the emergence of the third dominant follicle. On the contrary, Deslorelin implants of 2100 micrograms drastically altered the P4 profiles and follicle dynamics.

Animals↗
PubMed1991

[Contraception with cyclic administration of buserelin and gestagens: increase in testosterone and free testosterone serum concentration].

During contraception with the LH-RH analogue buserelin, some women developed mild androgenic symptoms. Therefore, we investigated in 10 women various hormonal serum parameters during one cycle of treatment with daily 300 micrograms buserelin intranasally (day 1-22) and 5 mg medroxyprogesterone acetate (MPA) orally (day 16-22), and, after a washout cycle, during another cycle of treatment with daily 300 micrograms buserelin intranasally (day 1-15) and 5 mg norethisterone acetate (NETA) orally (day 16-22). The serum parameters were investigated on day 1, 15 and 21 during the 4 hours after administration of the drugs. During the treatment, LH release was significantly reduced, whereby additional MPA had no effect whatsoever, while NETA profoundly suppressed LH. During treatment with buserelin and MPA, the average oestradiol levels remained unaltered, but were significantly suppressed by 65% during intake of NETA. Contrary to 17 alpha-hydroxyprogesterone, which did not change, serum testosterone was significantly increased by 30% when buserelin was given with or without MPA, while NETA had no effect. During both regimens, the serum concentrations of SHBG were reduced by 15 to 25%, and those of free testosterone were increased by 30 to 50%. These alterations in hormonal parameters may have contributed to the development of seborrhoeic symptoms and acne of the facial skin which were observed in 6 of the 10 women treated with intranasal buserelin for contraception.

Administration, Intranasal↗