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1.
Reprod Toxicol ; 129: 108683, 2024 10.
Article in English | MEDLINE | ID: mdl-39121978

ABSTRACT

The present study investigated the effect of adding allopathic doxorubicin (DOX 0.3 µg/mL), the vehicle of ultradiluted/dynamized doxorubicin (0.2 % ethanol), different dynamizations of ultradiluted/dynamized doxorubicin (DOX 6CH, DOX 12CH and DOX 30CH), both in the absence or presence of chemical stress induced by doxorubicin at 0.3 µg/mL on follicular survival and activation, antioxidant capacity of the medium, Catalase activity (CAT), production of reactive protein thiol, maintenance of type I and III collagen fibers and accumulation of lipofuscin in porcine ovarian tissue cultured in vitro for 48 hours. To do this, part of the ovarian tissue fragments was fixed for the uncultured control and the rest were cultured in: MEM (cultured control), DOX 0.3 µg/mL, Ethanol, DOX 6CH, DOX 12CH, DOX 30CH, DOX (0.3 µg/mL) + DOX 6CH, DOX (0.3 µg/mL) + DOX 12CH, DOX (0.3 µg/mL) + DOX 30CH treatments. The results showed that, in general, ultradiluted/dynamized doxorubicin (DOX 6CH, DOX 12CH and DOX 30CH) mitigated the toxic effect of allopathic doxorubicin (0.3 µg/mL) on the morphology of preantral follicles, the content of type I and III collagen fibers, and the production of lipofuscin in the tissue. However, only DOX (0.3 µg/mL) + DOX 6CH attenuated the oxidative stress induced by DOX (0.3 µg/mL), maintaining adequate CAT activity that was similar to the uncultured control. Additionally, when the three isolated ultradiluted/dynamized doxorubicin were considered, only DOX 12CH increased the reduced thiol levels compared to the uncultured control and MEM. In conclusion, supplementing the culture medium with ultradiluted/dynamized DOX (DOX 6CH, DOX 12CH and DOX 30CH) attenuated the toxicity induced by allopathic doxorubicin during the in vitro culture of pig preantral follicles enclosed in ovarian tissue.


Subject(s)
Antibiotics, Antineoplastic , Doxorubicin , Ovarian Follicle , Animals , Doxorubicin/toxicity , Female , Swine , Antibiotics, Antineoplastic/toxicity , Ovarian Follicle/drug effects , Catalase/metabolism , Tissue Culture Techniques , Lipofuscin/metabolism , Oxidative Stress/drug effects , Antioxidants/pharmacology , Collagen Type I/metabolism , Ovary/drug effects , Sulfhydryl Compounds/metabolism , Collagen Type III/metabolism
2.
BioDrugs ; 17(4): 288-9, 2003.
Article in English | MEDLINE | ID: mdl-12899646

ABSTRACT

Ferring Pharmaceuticals (US) is developing a highly purified form of urofollitropin [human follicle-stimulating hormone, hFSH, FERRING hFSH, Bravelle] for use in ovarian stimulation in fertility treatments. The highly purified human-derived follicle-stimulating hormone (HP-FSH), administered by either intramuscular (IM) or subcutaneous (SC) injection, was in phase III trials in the US and in May 2002 the product received US FDA approval for use in conjunction with human chorionic gonadotropin for infertility patients undergoing ovulation induction. The product will be marketed as Bravelle. Ferring Pharmaceuticals has also submitted a New Drug Application for additional indications for Bravelle in infertility treatment, which is currently under review by the US FDA. Bravelle is produced from the urine of menopausal women and has been shown to be as effective as Organon's recombinant FSH product, Follistam. Preclinical studies have shown that Ferring Pharmaceuticals' hFSH can be mixed in the same syringe as purified human menopausal gonadotropin (hMG) to reduce the number of daily injections required in ovarian stimulation protocols without altering the bioactivity of FSH or luteinising hormone. In addition, Ferring Pharmaceuticals' hFSH administered SC or IM showed positive results compared with SC Repronex in a randomised, open-label study in patients undergoing in vitro fertilisation.Ferring Pharmaceuticals has teamed up with the American Infertility Association and RESOLVE: the National Infertility Association to improve access to infertility treatment in the US, with the recent launch of the 'Bravelle' HEART (Helping Expand Access to Reproductive Therapy) Programme. The programme is intended to provide urofollitropin treatment at significant cost savings to patients and their physicians. Serono is also developing a highly purified urofollitropin product.


Subject(s)
Follicle Stimulating Hormone/pharmacology , Follicle Stimulating Hormone/therapeutic use , Adolescent , Adult , Clinical Trials, Phase II as Topic , Drug Administration Schedule , Drug Approval , Drug Combinations , Female , Fertility Agents, Female/administration & dosage , Fertility Agents, Female/pharmacokinetics , Fertility Agents, Female/therapeutic use , Fertilization in Vitro/drug effects , Fertilization in Vitro/methods , Follicle Stimulating Hormone/chemistry , Humans , Infertility/drug therapy , Injections, Intramuscular , Injections, Subcutaneous , Menotropins/administration & dosage , Menotropins/pharmacology , Ovary/drug effects , Pregnancy , Pregnancy Rate , Premenopause/drug effects , United States , United States Food and Drug Administration
3.
Contraception ; 46(5): 477-88, 1992 Nov.
Article in English | MEDLINE | ID: mdl-1458894

ABSTRACT

The performance of a new low-dose oral contraceptive (Mercilon) containing only 20 micrograms ethinyloestradiol combined with 150 micrograms desogestrel is reviewed. Eight multicentre clinical trials have been completed and provide information on 10,672 women studied over 73,477 cycles. The high efficacy of Mercilon was indicated by the finding that only 10 pregnancies were reported; nine of these occurred in women who omitted to take Mercilon on a number of days and only one in a woman who took all the tablets according to instructions. Cycle control was good; as with all oral contraceptives, the incidence of breakthrough bleeding and spotting was highest in the first treatment cycle and by the sixth treatment cycle the values were usually < 5% and < 7%. More than 80% of women had regular cycles. Side effects were few, the most common being headache, nausea and breast tenderness with incidences in the sixth treatment cycle of less than 2%, 6% and 6%, respectively. There were no significant changes in body weight or blood pressure. Pharmacodynamic investigations showed no adverse effects. Only 1 of 5 studies found an increased response to a glucose tolerance test compared to the pretreatment test. In 8 of 10 studies, serum HDL-C concentrations increased on treatment and this was associated with increases in apoproteins A1 and A2. Serum triglyceride levels also increased but no change occurred in serum cholesterol or LDL-C levels. Haematological factors were assessed in 8 studies and only minor changes were observed. Serum binding protein (SHBG, CBG, caeruloplasmin) concentrations increased and serum androgen levels decreased. Measurements of blood FSH, LH, oestradiol and progesterone indicated adequate inhibition of ovulation. Mercilon is the only oral contraceptive containing 20 micrograms ethinyloestradiol to have high efficacy, to have no adverse pharmacodynamic effects and, importantly, to produce an acceptable bleeding pattern not significantly different from that of oral contraceptives with a higher content of ethinyloestradiol.


Subject(s)
Pancuronium/analogs & derivatives , Adult , Blood Proteins/analysis , Carbohydrate Metabolism , Clinical Trials as Topic , Female , Humans , Lipid Metabolism , Ovary/drug effects , Pancuronium/adverse effects , Pancuronium/pharmacology , Pituitary Gland/drug effects
4.
Contraception ; 56(1): 23-30, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9306028

ABSTRACT

In a double-blind randomized study, the suppression of ovarian activity and anti-conceptive effects on the cervix and endometrium were assessed during administration of two low-dose monophasic oral contraceptives (20 micrograms ethinyl estradiol [EE], 500 micrograms norethisterone--Eve 20 [Grünenthal, Aachen, Germany]; 20 micrograms EE, 150 micrograms desogestrel --Lovelle [Organon, Munich, Germany]). One hundred eighteen healthy women (ages: 18-35 years) were studied in 10 investigation centers during medication with either Eve 20 (n = 59) or Lovelle (n = 59). During three treatment cycles, ovarian activity was evaluated by sonographic determination of follicle-like structures (FLS) and by simultaneous assessment of serum endocrine profiles (gonadotropins LH and FSH, ovarian steroids estradiol [E2] and progesterone [P]). While on either treatment, no ovarian activity (as judged by no FLS and/or reduced sex steroid levels) was found in 90.8% (Eve 20) and 97.2% (Lovelle) of all investigated cycles. Follicular activity or cyst formation were detected in 18 of 173 cycles (Eve 20) and in 5 of 175 cycles (Lovelle), respectively. Gonadotropin levels were suppressed (LH < 6 IU/L, FSH < 8 IU/L) in most treatment cycles (Eve 20 76.6% vs. Lovelle: 84.8%). Serum E2 concentrations exceeding 0.1 nmol/L indicated residual follicular activity in 19.3% (Eve 20) versus 12.2% (Lovelle) of all cycles. An estimated by serum P levels over 5 nmol/L, ovulation had presumably occurred in 4.1% (Eve 20) versus 2.9% (Lovelle) of treatment cycles. However, when the sonographical and endocrinological data were combined, no ovulation was documented in any pill cycle. The quality and quantity of the cervical mucus was found to be minimal in the majority of women. Moreover, the endometrial layer was determined to be low by ultrasound during most pill cycles, indicating equally strong suppressive effects on endometrial receptivity by the two contraceptives. These observations suggest that ovarian activity is suppressed in the majority of cycles during use of low-dose contraceptives. This effect may mainly be medicated by pronounced suppression of serum gonadotropin levels. Strong anti-conceptive effects of these formulations on both cervical permeability and endometrial receptivity are additional factors ensuring the contraceptive efficacy of these formulations.


PIP: The impact of two low-dose monophasic oral contraceptives (OCs) on suppression of ovarian activity, cervical permeability, and endometrial receptivity was investigated in a randomized double-blind study involving 118 healthy women 18-35 years of age recruited from 10 study centers in Germany. 59 women received Eve (20 mcg of ethinyl estradiol and 500 mcg of norethisterone) and 59 were given Lovelle (20 mcg of ethinyl estradiol and 150 mcg of desogestrel) for a total of 3 cycles. No ovarian activity, as assessed by sonographic determinations of follicle-like structures and serum endocrine profiles, was detected in 90.8% of cycles of Eve users and 97.2% of cycles in the Lovelle group. Follicular activity or cyst formation was found in 18 of 173 cycles of Eve users and 5 of 175 cycles of Lovelle users. Gonadotropin levels were suppressed (luteinizing hormone under 6 IU/L and follicle-stimulating hormone less than 8 IU/L) in 76.6% of treatment cycles in the Eve group and 84.8% of cycles in the Lovelle group. Serum estradiol concentrations exceeding 0.1 nmol/L, indicative of follicular activity, were recorded in 19.3% of cycles of Eve users and 12.2% of cycles in the Lovelle group. Although serum progesterone levels were over 5 nmol/L in 4.1% of cycles in the Eve group and 2.9% of those in the Lovelle group, consolidation of sonographic and endocrinologic data failed to document ovulation in any treatment cycles. The quantity and quality of cervical mucus was minimal in most women in both groups. Finally, the endometrial layer was determined to be low by ultrasonography during most pill cycles, confirming the OCs' equally strong suppressive effects on endometrial receptivity.


Subject(s)
Cervix Mucus/drug effects , Contraceptives, Oral, Combined/pharmacology , Contraceptives, Oral, Synthetic/pharmacology , Endometrium/drug effects , Ovary/drug effects , Adult , Cervix Mucus/physiology , Cohort Studies , Desogestrel/pharmacology , Double-Blind Method , Estradiol/blood , Estradiol/metabolism , Ethinyl Estradiol/pharmacology , Female , Follicle Stimulating Hormone/blood , Follicle Stimulating Hormone/metabolism , Gonadotropins/blood , Gonadotropins/metabolism , Humans , Luteinizing Hormone/blood , Luteinizing Hormone/metabolism , Menstrual Cycle/drug effects , Menstrual Cycle/physiology , Norethindrone/pharmacology , Ovary/diagnostic imaging , Ovary/physiology , Progesterone/blood , Progesterone/metabolism , Steroids/blood , Steroids/metabolism , Ultrasonography
5.
Contraception ; 47(3): 251-61, 1993 Mar.
Article in English | MEDLINE | ID: mdl-8462316

ABSTRACT

The properties of a single contraceptive subdermal implant releasing 3-ketodesogestrel were assessed in fifteen women over twelve months. Serum levels of 3-ketodesogestrel were monitored regularly following insertion and after removal. The mean serum level of 3-ketodesogestrel was 245 pg/ml after 72 h (steady state) and 176 pg/ml after twelve months. All volunteers demonstrated ovulation inhibition throughout the study. Transient oestradiol peaks occurred during the study. No luteal activity was noted. The cervical mucus was rapidly rendered hostile to sperm migration. Two women withdrew from the study during the first six months for medical reasons. Both volunteers cited bleeding irregularity as the main cause, one complaining of oligomenorrhoea, the other of prolonged bleeding/spotting episodes. A small but significant increase in weight was noted during the study period.


PIP: 15 sterilized women participated in a clinical trial of the implant Implanon (Organon), a single ethylene vinyl acetate rod containing 60 mg 3-ketodesogestrel (3-KDG), the metabolite of desogestrel. The rod is 40 mm long, 2 mm in diameter and is packaged in its inserter. In this trial the implants were treated to simulate the 2nd year of use. The study subjects underwent intensive hormone and ultrasound monitoring for 72 hours after insertion, twice weekly for 6 weeks and at 6-month intervals. 13 women completed 6 months, 7 completed 12 months, and 5 continued the trial 24 months. There were no complications related to insertion or removal. 3-KDG levels rose to a steady state of 245 pg/ml by 72 hours, then fell to a mean of 17 pg/ml at 12 months. 90 pg/ml of 3-KDG is the critical serum level for anovulation. After removal, 3-KDG declined to 54 pg/ml in 3 days. Follicle development tended toward small follicles or those larger than 10 mm. There was no luteal activity, and LH, FSH and progesterone remained in the follicular phase range. Estradiol levels were not low enough to risk osteoporosis. There was no significant change in serum sex hormone binding globulin. Systolic blood pressure decreased significantly at 12 months; mean weight gain was 3.7 kg (range from loss of 4 kg to gain of 22 kg); a variety of bleeding irregularities were recorded by individual women.


Subject(s)
Desogestrel/pharmacology , Menstruation/drug effects , Ovary/drug effects , Progesterone Congeners/pharmacology , Adolescent , Adult , Blood Pressure/drug effects , Body Weight/drug effects , Cervix Mucus/drug effects , Desogestrel/administration & dosage , Desogestrel/adverse effects , Desogestrel/pharmacokinetics , Drug Implants , Female , Gonadal Steroid Hormones/blood , Humans , Ovarian Follicle/diagnostic imaging , Ovarian Follicle/drug effects , Ovarian Follicle/physiology , Ovary/physiology , Ovulation/drug effects , Progesterone Congeners/administration & dosage , Progesterone Congeners/adverse effects , Progesterone Congeners/pharmacokinetics , Sex Hormone-Binding Globulin/analysis , Ultrasonography
6.
Eur J Pharmacol ; 651(1-3): 227-33, 2011 Jan 25.
Article in English | MEDLINE | ID: mdl-21115001

ABSTRACT

Corifollitropin alfa (Elonva®, MSD, previously N.V. Organon or Schering-Plough Oss, The Netherlands) is a newly developed sustained follicle stimulant composed of the α subunit of human follicle-stimulating hormone (FSH) and a hybrid ß subunit formed by fusion of the human chorionic gonadotropin ß subunit carboxy terminal peptide with the ß subunit of human FSH. Binding characteristics of corifollitropin alfa at the rat FSH receptor and transactivation properties at the rat FSH receptor, human luteinizing hormone (LH) receptor, and human thyroid-stimulating hormone receptor (TSH receptor) were assessed in vitro. Bioactivity of corifollitropin alfa in rats was also assessed. Serum corifollitropin alfa levels in rats and dogs were used to derive the main pharmacokinetic parameters of corifollitropin alfa. Binding and transactivation profile of corifollitropin alfa to rat FSH receptor was specific and comparable to that of recombinant human FSH, with no intrinsic TSH receptor or LH receptor activation. From pharmacokinetic studies, circulating half-life of corifollitropin alfa was calculated to be 17.3h in rats and 46.9h in dogs, 1.5- to 2-fold longer than recombinant FSH. Corifollitropin alfa demonstrated a 2- to 4-fold increase in bioactivity (ovarian weight, serum estradiol and progesterone, ovulated ova) over recombinant FSH across all in vivo parameters assessed. These data demonstrate that corifollitropin alfa is a specific ligand with high affinity for FSH receptor, lacking intrinsic activity for LH receptor and TSH receptor. By virtue of its increased in vivo half-life, corifollitropin alfa can be a valuable alternative to FSH by acting as a sustained follicle stimulant.


Subject(s)
Drug Discovery , Follicle Stimulating Hormone, Human/pharmacology , Animals , CHO Cells , Cricetinae , Cricetulus , Dogs , Estradiol/blood , Female , Follicle Stimulating Hormone, Human/metabolism , Follicle Stimulating Hormone, Human/pharmacokinetics , Humans , Organ Size/drug effects , Ovary/anatomy & histology , Ovary/drug effects , Progesterone/blood , Rats , Receptors, FSH/genetics , Receptors, FSH/metabolism , Time Factors , Transcriptional Activation/drug effects
7.
Nan Fang Yi Ke Da Xue Xue Bao ; 28(6): 982-5, 2008 Jun.
Article in Zh | MEDLINE | ID: mdl-18583244

ABSTRACT

OBJECTIVE: To observe the protective effect of Oviductus Ranae (OR) capsules on the reproductive organs in an aged mouse model established by D-galactose injection. METHODS: Forty-eight female Kunming mice were randomly divided into 4 equal groups, namely the high- and low-dose OR groups, diethylstilbestrol (DT) group, and model group. The mice received subcutaneous injection of D-galactose for 6 weeks to establish aging models. Another 12 mice were injected daily with normal saline (NS) to serve as the normal control group. From the third week of the experiment, the mice were given oral OR at low or high doses (in the OR groups) or vegetable oil (in the model or control groups) till the sixth week. In the last two weeks, the vaginal smears were obtained from the mice for evaluating the changes of the vaginal keratinocytes and counting the days of estrus. After completion of drug administration, all the mice were sacrificed and the serum content of estradiol (E(2)) was detected by radioimmunoassay, with the ovarian and uterine indices determined. The ovarian and uterine pathologies were observed using HE staining, and SOD and MDA activities in the ovary and uterus were also assessed. RESULTS: OR obviously increased E(2) level and the ovarian and uterine indices in the aged mice, also alleviating the pathological change of the ovary and uterus. OR substantially depressed MDA content and enhanced SOD activity in the ovary and uterus. CONCLUSION: OR has definite antioxidative effects and ameliorates the degenerative changes of the reproductive organs in mouse models of aging.


Subject(s)
Aging , Materia Medica/pharmacology , Ovary/drug effects , Uterus/drug effects , Animals , Capsules , Estradiol/blood , Female , Mice , Ovary/physiology , Random Allocation , Uterus/physiology
8.
Acta Obstet Gynecol Scand ; 54(3): 217-21, 1975.
Article in English | MEDLINE | ID: mdl-1163213

ABSTRACT

The plasma levels of progesterone and oestrogens were measured during treatment with an oral contraceptive containing 37.5 mug of ethinyl oestradiol and 1 mg of lynestrenol (= 3-desoxy-17alpha-ethinyl-19-nortestosterone) (Ovostat 1375, Organon, Oss, Holland). Blood samples were taken every day during 9 complete cycles in 5 healthy women. The plasma levels of progesterone were in the range of those found during the early follicular phase of the normal women. No ovulation seemed to have occurred. The mean plasma levels of oestrogens (oestradiol and oestrone) during treatment were below those found during early follicular phase of 34 normal cycles although overlapping of values occurred. The ratio between oestradiol and oestrone during treatment was 1:2 vs. 1:1 during the early follicular phase of the normal cycles. In two cycles treatment was started during the midcyclic rise of oestrogens. No rise of progesterone indicating corpus luteum formation was found. Despite the low amount of oestrogen in the drug the ovaries appeared to secrete minimal amounts of sex steroids. The lynestrenol content is likely to be partly responsible for the inhibition of ovulation and the additional suppression of steroidogenesis.


Subject(s)
Estrogens/blood , Ethinyl Estradiol/administration & dosage , Lynestrenol/administration & dosage , Progesterone/blood , Adult , Depression, Chemical , Estradiol/blood , Estrone/blood , Female , Humans , Menstruation/drug effects , Ovary/drug effects
9.
Zentralbl Gynakol ; 119(11): 538-44, 1997.
Article in German | MEDLINE | ID: mdl-9480608

ABSTRACT

In a double-blind randomized study, the suppression of ovarian activity, the effects on the cervix and endometrium, menstrual bleeding patterns and overall tolerance were assessed during administration of two low-dose oral contraceptives (20 micrograms ethinylestradiol EE, 500 micrograms norethisterone--Eve 20, Grünenthal, Aachen; 20 micrograms EE, 150 micrograms Desogestrel--Lovelle, Organon, Munich), 118 healthy women (ages: 18 to 35 years) with comparable bioprofiles (height, weight, menstrual cycle patterns) were studied in 10 investigation centres during medication with either Eve 20 (n = 59) or Lovelle (n = 59). During 3 treatment cycles, ovarian activity was evaluated by sonographic determination of follicular size and by simultaneous assessment of serum endocrine profiles (gonadotropins LH and FSH, ovarian steroids estradiol [E2] and progesterone [P]). Treatment cycles 4 to 6 served to evaluate the patterns of menstrual bleeding and the overall subjective tolerance on each contraceptive. While on the preparations, no ovarian activity (as judged by a lack of follicular growth and suppressed sex steroid levels) was found in over 90% of all investigated cycles. Follicular activity and/or cyst formation were detected in 18 of 173 cycles (Eve 20) and in 5 of 175 cycles (Lovelle) respectively. Gonadotropin levels were suppressed (LH < 6 IU/l, FSH < 8 IU/l) in most treatment cycles (Eve 20: 76.6% vs. Lovelle: 84.8%). Serum E2 concentrations exceeding 0.1 nmol/l indicated residual follicular activity in 19.3% (Eve 20) vs. 12.2% (Lovelle) of all cycles. As estimated by serum P levels over 5 nmol/l, ovulation had presumably occurred in 4.1% (Eve 20) vs. 2.9% (Lovelle) of treatments respectively. However, when the sonographic and endocrinological data were combined, no ovulation was documented in any treatment cycle. In addition, the quality of the cervical mucus was minimal and a low endometrial thickness was found in the majority of women, indicating strong progestogen effects of both contraceptives. Menstrual irregularities (intermenstrual spotting, break-through bleeding) occurred initially on each preparation, but were mostly resolved when the pills were continued. The acceptance of each investigated drug was rated as very good or good by most subjects. These observations allow us to conclude that the rate of ovarian suppression with inhibition of follicular activity is high under low-dose oral contraceptives. The different progestogens as components of these contraceptive pills display equally good anti-conceptive effects on both the cervix and the endometrium. Furthermore, the rate of irregular menstrual bleeding is acceptable for these low-dose contraceptives. The high acceptance of each preparation suggests that such agents will have a high rate of acceptability in clinical use.


Subject(s)
Contraceptives, Oral, Synthetic/administration & dosage , Desogestrel/administration & dosage , Menstrual Cycle/drug effects , Ovary/drug effects , Adult , Contraceptives, Oral, Synthetic/adverse effects , Desogestrel/adverse effects , Dose-Response Relationship, Drug , Double-Blind Method , Ethinyl Estradiol/administration & dosage , Ethinyl Estradiol/adverse effects , Female , Gonadal Steroid Hormones/blood , Humans , Norethindrone/administration & dosage , Norethindrone/adverse effects , Ovarian Function Tests
10.
J Endocrinol Invest ; 23(3): 151-7, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10803471

ABSTRACT

The antiprogestin (AP) RU38486 (RU) blocks progesterone (P) and glucocorticoid (G) actions. Administration of 4 mg RU on proestrous morning to cyclic rats dissociates LH and FSH secretion on proestrous afternoon, early estrus and on estrous afternoon. In order to ascertain which action blocked by RU is predominant in the control of periovulatory LH and FSH secretion, a study was made on the effects of: a) 1 or 4 mg of ZK98299 (ZK) (type I P antagonist; Schering), b) 2 or 8 mg of Org31710 (OR) (type II P antagonist lacking anti-G actions; Organon) or c) 1 or 4 mg of RU (type II P antagonist; Exelgyn) to 4-day cyclic rats on proestrous morning on serum concentrations of LH, FSH, inhibin-alpha (I), estradiol-17beta (E), progesterone (P) and corticosterone (B) at 18:30 h on proestrus and at 02:00 and 18:30 h on estrus. Controls, receiving 0.2 ml oil, had elevated serum concentrations of all six hormones on proestrous afternoon; at early estrus, only serum concentrations of FSH and P remained elevated, and, on estrous afternoon, all hormones but I and B, that peaked again, had reached their lowest serum levels. All AP treatments except 1 mg ZK had the same effects. On proestrous afternoon serum LH concentrations were reduced and serum FSH concentrations were suppressed whereas serum levels of I, E, P and B were unaffected. At early estrus, basal serum concentrations of LH and E increased while FSH secretion was abolished. Serum levels of I, P and B did not differ from controls. AP treatments increased basal LH concentration, hyperstimulated FSH secretion and reduced serum I concentration on the afternoon of estrus. E, P and B serum levels did not differ from controls at this stage. Treatment with 1 mg ZK was less effective in reducing serum FSH on proestrous afternoon and at early estrus, and had no effect on serum concentrations of any hormone on estrous afternoon. These results indicate that blockade of P receptor activation by P is, predominantly, the mechanism of AP action on periovulatory gonadotropin secretion in rats.


Subject(s)
Adrenal Glands/metabolism , Estrenes/pharmacology , Furans/pharmacology , Gonanes/pharmacology , Hormone Antagonists/pharmacology , Mifepristone/pharmacology , Ovary/metabolism , Ovulation/physiology , Pituitary Gland, Posterior/metabolism , Adrenal Glands/drug effects , Animals , Corticosterone/blood , Female , Follicle Stimulating Hormone/blood , Inhibins/blood , Luteinizing Hormone/blood , Ovary/drug effects , Pituitary Gland, Posterior/drug effects , Progesterone/blood , Rats , Rats, Wistar
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