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At least 19 recordsLinked to original sources

PubMed1976

Plasma gonadotropin and gonadotropin-releasing hormone levels after intranasal administration of gonadotropin releasing hormone.

Intranasal administration of gonadotropin hormone (GnRH) in doses ranging from 2-4 mg produced a consistently prolonged LH response in patients with secondary amenorrhea. In 4 cases, a delayed secondary rise occurred. A similarly prolonged FSH response was observed in the majority of patients. Six hours after intranasal GnRH, FSH and LH values were well above basal levels and were higher than those observed at a similar interval after intravenous GnRH. Plasma GnRH levels after intranasal administration failed to achieve the high peaks found after the intravenous route but maintained elevated levels for at least an hour and often longer. Despite the much lower plasma GnRH levels, intranasal GnRH produced a sustained effect on LH and FSH secretion, greater than GnRH given by the intravenous route.

Administration, Intranasal↗

PubMed1976

Actions of pregnant mare serum gonadotropin in the immature female rat: correlative changes in blood steroids, gonadotropins, and cytoplasmic estradiol receptors of the anterior pituitary and hypothalamus.

Several blood steroids, serum gonadotropins and cytosol estradiol receptors of the anterior pituitary and hypothalamus were quantified in immature female rats which were induced to ovulate with pregnant mare's serum gonadotropin (PMSG). Studies revealed that serum levels of progesterone, 17-hydroxyprogesterone, testosterone, androstenedione and estradiol were initially elevated at 6 PM (day 30) after administration of 8 IU of PMSG at 10 AM day 30. Serum levels of estradiol and testosterone rose progressively from day 30 through the AM of day 32. A further increase in serum concentrations of progesterone, 17-hydroxyprogesterone, androstenedione, testosterone, and dehydroepiandrosterone occurred on the PM of day 32 whereas serum estradiol levels declined. Serum levels of all steroids declined on the day of estrus (33) and only progesterone levels were further elevated on day 34 (diestrus). Dihydrotestosterone concentrations were minimally altered by PMSG treatment. Saline administration resulted in no significant alterations in levels of any steroid quantified from day 29 to 34 in control animals. A progressive decline in cytosol estradiol receptor content of the anterior pituitary and hypothalamus was documented following PMSG treatment of intact female rats; there was no depletion of receptors following PMSG administration to ovariectomized immature rats. Maximal depletion of cytosol estradiol receptors occurred on day 32 with replenishment of cytosol estradiol receptor levels on estrus (day 33). The preovulatory gonadotropin surge was found to occur on the PM of day 32 after maximal receptor depletion. The cycle of depletion and replenishment of receptors was repeated during a second spontaneous estrous cycle four days later which coincided with a rise and fall in serum estradiol levels. It is suggested that the depletion of cytosol estradiol receptors of the anterior pituitary/hypothalamic unit may be causally related to the preovulatory gonadotropin surge resulting from PMSG administration to immature female rats. In addition, changes in blood steroids and gonadotropins after PMSG treatment are similar to those reported for proestrus-estrus-diestrus I of the normal adult estrous cycle. These findings further demonstrate the validity of the PMSG-primed immature female rat preparation as a model for the estrous cycle of the adult rat.

Androstenedione↗

PubMed1977

Gonadotropin-inhibitory contaminants in partially purified pharmaceutical preparations of human chorionic gonadotropin.

Various commercial preparations of partially purified human chorionic gonadotropin, inactivated by heating, inhibited the uterine growth induced in immature mice with the same active gonadotropins as well as spontaneous uterine growth. The more purified preparations of chorionic gonadotropin failed to produce these effects after inactivation by boiling, suggesting that the inhibitory activity is not generated from gonadotropin by the procedure but may be related to some contaminant similar to the gonadotropin-inhibitory substance previously found in human urine.

Animals↗

PubMed1975

Fish gonadotropin(s). III. Evidence for more than one gonadotropin in chum salmon pituitary glands.

Two proteins with gonadotropin activity have been isolated from a highly purified chum salmon (Oncorhynchus keta) gonadotropin preparation (G-75 Fraction II) by chromatography on DEAE Bio Gel A. These gonadotropins exhibited distinct behaviour in polyacrylamide gel electrophoresis, chromatography on Sephadex G-75 superfine, and ratios of cAMP stimulation in immature rainbow trout ovaries and testes. Rechromatography of G-75 Fraction II on Sephadex G-75 superfine gave a symmetrical protein peak with a coincident cAMP activity profile. Repeated freezing and thawing elicited a shift in the cAMP activity profile toward the trailing edge of the protein peak. Data are discussed in terms of two gonadotropin molecules which respond differently to phase changes. Charge polymorphism was exhibited by isoelectric focusing in polyacrylamide gels of one of the DEAE fractions. Five UV absorbing bands were observed which stimulated cAMP production in immature rainbow trout gonads. Three of these bands increased adenyl cyclase activity in trout ovaries and testes. One of the bands stimulated cAMP production primarily in trout testes and the other stimulated trout ovaries, providing evidence for two gonadotropins, each of which is sex specific.

Animals↗

PubMed1979

[Gonadotropin secretion following pernasal stimulation with synthetic gonadotropin releasing hormone (GnRH) and a highly effective GnRH-analog in healthy men and prepubertal boys].

Potent long acting analogs of GnRH are of great interest especially in view of pernasal (p.n.) treatmen of hypogonadism of hypothalamic origin and of cryptorchidism. To find the necessary p.n. dosage of such a substance, serum LH and FSH were measured in 6 normal adult human males after p.n. application of various doses of D Leu6-des-Gly10-GnRH ethylamide. 50 microgram of the GnRH analog were necessary to obtain increased serum gonadotropins over a period of at least 8 hours. By repeated p.n. application of 200 microgram of synthetic GnRH every 2 hours in 6 normal adult males a considerable increase of serum gonadotropins could be demonstrated as well. Pernasal application of 200 microgram GnRH repeated at an interval of 1 hour in 3 cryptorchid boys produced a distinct increase of the serum gonadotropins. The intraindividual comparison of 200 microgram GnRH and 20 microgram of the GnRH analog in one boy showed equivalent net increases of the gonadotropins. With the analog the gonadotropin increase lasted for about 6 hours.

Administration, Intranasal↗

PubMed1978

Observations on 320 infertile patients treated with human gonadotropins (human menopausal gonadotropin/human chorionic gonadotropin).

From 1964 to 1975, 320 patients with failure of ovulation were treated with human gonadotropins (human menopausal gonadotropin [HMG]/human chorionic gonadotropin [HCG]). Estimation of the pituitary and ovarian function of each patient rather than classification into clinical groups contributed positively to the selection of patients. The dosage schedules used for the patients should be considered conservative, insofar as the amount of HMG and HCG administered per treatment cycle is concerned. The response to human gonadotropins was evaluated mainly according to excretion levels of estrogen and pregnanediol. Of the 320 patients, 256 ovulated at least once during treatment with gonadotropins (80%). Ovarian hyperstimulation syndrome was encountered in 22 patients (6.8%). Pregnancy occurred in 163 patients (50.9%) and in some of them twice, so that the total number of pregnancies was 206. Fifteen pregnancies were multiple (all of them twins). Of 197 pregnancies followed, 43 ended in abortion and 36 in premature labor. Cesarian section was performed in 21 cases.

Chorionic Gonadotropin↗

PubMed1979

Between-ovary interaction in the regulation of follicle growth, corpus luteum function, and gonadotropin secretion in the primate ovarian cycle. III. Temporal and spatial dissociation of folliculogenesis and negative feedback regulation of tonic gonadotropin release after luteectomy in rhesus monkeys.

This study was designed to examine effects of previous ovarian status on subsequent follicle growth and the role of between-ovary communication in the regulation of folliculogenesis and gonadotropin secretion during the primate ovarian cycle. Responses to luteectomy were compared in two groups of rhesus monkeys. In the first, follicle growth and corpus luteum function had been constrained chronically to a single ovary by hemiovariectomy performed 66--258 days earlier; the second group was composed of intact monkeys that underwent contralateral wedge resection at luteectomy. In each group, luteal ablation was followed by a prompt fall in serum progesterone levels, a premature onset of menses, and the next preovulatory gonadotropin surges 14.7 +/- 1.1 or 15.4 +/- 1.4 days later (mean +/- SE; P greater than 0.25). Although the patterns of circulating estradiol before and after ablation in each group were superimposable, luteectomy in monkeys lacking a contralateral ovary was followed by a large (2- to 4-fold) and prolonged (7--10 days) increase in serum FSH, whereas in monkeys with two ovaries, serum FSH levels exhibited only a small short-lived rise. The findings indicate that 1) prior chronic constraint of ovarian function to a single ovary did not alter the overall time course of new follicle growth culminating in ovulation after luteectomy; 2) the contralateral ovary provided the principal negative feedback regulation of gonadotropin secretion for some time after luteectomy even though it may not have been the exclusive site of new follicle growth; 3) whereas the ability of the luteectomized ovary to regulate tonic gonadotropin secretion was temporarily impaired, its ability to support the customary temporal pattern of follicle growth after luteal ablation was not; 4) some (contralateral) ovarian factor other than estradiol or progesterone apparently made a major contribution to the regulation of FSH secretion after luteectomy; and 5) folliculogenesis culminating in ovulation from a single follicle and the negative feedback regulation of tonic gonadotropin secretion in some circumstances may occur concurrently but separately on opposite ovaries or may occur at different times within the same ovary.

Animals↗

PubMed1977

Pregnant mare's serum gonadotropin. III. Hemispaying and the reversal of the antifertility faculty of pregnant mare's serum gonadotropin.

A single injection of 10 IU of pregnant mare's serum gonadotropin (PMSG) on day 5 of pregancy caused wastage of the fetoplacental unit by day 16 of pregnancy. Semispaying, which seems to subtract approximately 50% of the ovarian steroid contribution, at 24, 48, and 72 hours following the PMSG schedule prevented the antifertility faculty of the hormone preparation. However, hemicastration at 96 hours following the gonadotropin regimen was found to be ineffective, and 100% of the test animals showed complete termination of pregnancy. Experimental data collectively tempt us to propose that an estrogen excess, particularly of follicular origin in both ovaries, is essential for more than 72 hours following gonadotropin sensitization before the antifertility faculty of PMSG can be demonstrated.

Animals↗

PubMed1976

Evidence for a gonadotropin from nonpregnant subjects that has physical, immunological, and biological similarities to human chorionic gonadotropin.

Substances from urinary extracts of normal, nonpregnant subjects and human pituitary gonadotropin preparations were found to react similarly to human chorionic gonadotropin (hCG) in a radioimmunoassay system that is highly specific for hCG and without crossreactivity to human luteinizing hormone (hLH). The antiserum was produced in a rabbit immunized with a bovine albumin conjugate of the unique carboxyl-terminal peptide (residues 123-145) isolated from a tryptic digest of the reduced, S-carboxymethylated hCGbeta subunit. The antibody recognition site on the peptide was found to reside on the last 15 amino acid residues of the carboxyl-terminal peptide, as evidenced by the competitive binding activities against 125I-labeled hCG of a series of peptides chemically synthesized according to the carboxyl-terminal sequence of HCGbeta. In order to elucidate the nature of the crossreacting substance in urinary extracts, a human postmenopausal urinary preparation (Pergonal) and a kaolin-acetone extract of urine from a patient with Klinefelter's syndrome were subjected to gel chromatography on Sephadex G-100. The results indicate that fractions showing immunocrossreactivity with the antiserum to hCGbeta-carboxyl-terminal peptide coeluted with 125I-labeled hCG which was separated distinctly from hLH. The same fractions from this postmenopausal urinary gonadotropin preparation exhibited in vitro biological activity proportional to the immunocrossreactivity of the hCG-specific antiserum. Concentration of postmenopausal women's urine by acetone precipitation retained approximately five times more immunoreactivity per unit volume than kaolin-acetone extraction, when assayed with the antiserum to hCGbeta-carboxyl-terminal peptide.

Chorionic Gonadotropin↗

PubMed1979

Action of gonadotropin-releasing hormone and its superactive analogues on the anterior pituitary: the mechanism of release and synthesis of gonadotropins.

The role of prostaglandins (PG), their active intermediates or the adenylcyclase-cyclic AMP system for gonadotropin release and/or synthesis was evaluated by administering gonadotropin-releasing hormone (Gn-RH) and its superactive analog to normal and aspirin-treated rats. Serum LH levels, anterior pituitary malondialdehyde (MDA) content and cyclic AMP (cAMP) levels were followed. The pituitaries stimulated with Gn-RH or its superactive analog yielded more MDA and cAMP than the controls. Stimulation of the pituitary with the releasing hormones, after aspirin treatment, yielded 40--70% less MDA and lower LH values than the nontreated animals. The cAMP levels were not significantly lowered by the aspirin treatment. These studies suggest that the activation of the PG biosynthesis and the adenyl-cyclase-cyclic AMP system are not sequential but 2 separate physiological events. The active PG intermediates may only be responsible for the release of LH. It is not clear whether the activation of cAMP initiates also the processes preparatory to the synthesis of LH in the endoplasmic reticulum. In vivo studies in rats showed that the analogs (I and II) were 30 times more potent and had a more prolonged action on the pituitary (3 h) than Gn-RH. Ultrastructural studies on the anterior pituitary after hypophyseal stalk portal vessel infusion of Gn-RH and the analog (I and II) provided ample morphological evidence for both Gn-RH and analog induced gonadotropin-release and synthesis. The prolonged action of the superactive analog (I and II) on the gonadotrophs was also indicated by ultrastructural studies.

Animals↗

PubMed1976

Strength-duration characteristics of estrogen effects on gonadotropin response to gonadotropin-releasing hormone in women. II. Effects of varying concentrations of estradiol.

This study was designed to investigate the effect of varying concentrations of estradiol, administered to normal women, upon the gonadotropin response to synthetic gonadotropin-releasing hormone (GnRH or LRF). Beginning at 4 pm on the first day of the menstrual cycle, 19 studies were performed in subjects who received injections of estradiol benzoate (E2B every 12 h for 6 days). Concentrations of E2B administered (mug/kg/12 h) were: 0.3, 0.6, 1.25, 2.5, 3.75, and 5.0. Mean serum estradiol concentrations achieved at these respective concentrations of E2B were 43, 53, 91, 145, 195, and 305 pg/ml. Twelve h after the last E2B injection, an intravenous bolus of 100 mug GnRH was administered. Gonadotropin response to this dose of GnRH after E2B was compared with each subject's response in the early follicular phase of a previous (control) cycle during which no exogenous estradiol was administered.

Dose-Response Relationship, Drug↗

PubMed1978

Ectopic secretion of chorionic gonadotropin by a lung carcinoma. Pituitary gonadotropin and subunit secretion and prolonged chemotherapeutic remission.

The ability of tumor markers to improve cancer therapy is not established. We studied a man with a human chorionic gonadotropin (HCG)-secreting large cell carcinoma of the lung and gynecomastia. Preoperatively, levels of HCG (109 ng/ml), its alpha and beta subunits (3.2 and 21 ng/ml, respectively) and plasma estradiol were elevated. Despite apparently complete tumor resection and total resolution of gynecomastia, HCG titers remained elevated (3.3 ng/ml), heralding tumor recurrence three weeks later. Because the pathophysiologic consequences of the ectopic secretion of HCG on pituitary function are not established, we administered 100 microgram of gonadotropin-releasing hormone (LHRH) and observed a markedly delayed increase in pituitary gonadotropins. Early chemotherapy, guided by persistence of HCG, reduced HCG to undetectable levels, restored to normal the response to LHRH and resulted in a distinctly unusual 30-month complete remission. Use of HCG as a tumor marker levels is more sensitive than the symptom of gynecomastia and may permit detection of small, potentially curable tumor foci.

Carcinoma, Small Cell↗

PubMed1978

Gonadotropin and testosterone secretion in normal human males after stimulation with gonadotropin-releasing hormone (GnRH) or potent GnRH analogs using different modes of application.

Gonadotropin-releasing hormone (GnRH) and some potent long-acting GnRH analogs, applied by different routes of administration, were tested in six healthy human males. The effects on gonadotropin secretion were compared with the one after intravenous (i.v.) bolus injection of 25 microgram of GnRH. The net increase of luteinizing hormone (deltaLH) in serum produced by 25 microgram of GnRH i.v. was matched by subcutaneous (s.c.) injection of 100 microgram of GnRH, dissolved in 20% gelatin or without gelatin; 5 microgram of D-Ser (TBU)6-des-Gly10-GnRH-ethylamide i.v.; 5 microgram of D-Leu6-des-Gly10-GnRH-ethylamide i.v.; and 50 microgram of D-Trp6-des Gly10-GnRH-ethylamide given pernasally (p.n.). D-Leu6-des-Gly10-GnRH-ethylamide, 50 microgram p.n., produced one-half such increase as did also multiple p.n. administrations of 200 microgram of GnRH every 2 hours. With 100 microgram of GnRH and all analogs, elevation of serum LH lasted for about 7 to 9 hours. The longest elevation was observed with GnRH dissolved in gelatin and with D-Ser (TBU)6-des-Gly10-GnRH-ethylamide, as reflected by the greatest areas under the curves of net increase. The longer the duration of the action of LH secretion, the higher was the observed increase in follicle-stimulating hormone (FSH). Correlation between effect on LH secretion and testosterone secretion was not found. By infusion of 1 microgram/kg/hour od D-Leu6-des-Gly10-GnRH-Ethylamide in two men over a period of 15 hours, a plateau of gonadotropin levels was reached within 7 to 9 hours. These plateau levels, especially of FSH, were higher than after bolus injection or p.n. application.

Administration, Intranasal↗

PubMed1979

Receptor-mediated gonadotropin action in the ovary. Regulatory role of cyclic nucleotide phosphodiesterase(s) in intracellular adenosine 3':5'-cyclic monophosphate turnover and gonadotropin-stimulated progesterone production by rat ovarian cells.

The regulatory role of cyclic nucleotide phosphodiesterase(s) and cyclic AMP metabolism in relation to progesterone production by gonadotropins has been studied in isolated rat ovarian cells. Low concentrations of choriogonadotropin (0.4-5ng/ml) increased steroid production without any detectable increase in cyclic AMP, when experiments were carried out in the absence of phosphodiesterase inhibitors. The concentration of choriogonadotropin (10ng/ml) that stimulated progesterone synthesis maximally resulted in a minimal increase in cyclic AMP accumulation and choriogonadotropin binding. Choriogonadotropin at a concentration of 10ng/ml and higher, however, significantly stimulated protein kinase activity and reached a maximum between 250 and 1000ng of hormone/ml. Higher concentrations (50-2500ng/ml) of choriogonadotropin caused an increase in endogenous cyclic AMP, and this increase preceded the increase in steroid synthesis. Analysis of dose-response relationships of gonadotropin-stimulated cyclic AMP accumulation, progesterone production and protein kinase activity revealed a correlation between these responses over a wide concentration range when experiments were performed in the presence of 3-isobutyl-1-methylxanthine. The phosphodiesterase inhibitors papaverine, theophylline and 3-isobutyl-1-methylxanthine each stimulated steroid production in a dose-dependent manner. Incubation of ovarian cells with dibutyryl cyclic AMP or 8-bromo cyclic AMP mimicked the steroidogenic action of gonadotropins and this effect was dependent on both incubation time and nucleotide concentration. Maximum stimulation was obtained with 2mm-dibutyryl cyclic AMP and 8-bromo cyclic AMP, and this increase was close to that produced by a maximally stimulating dose of choriogonadotropin. Other 8-substituted derivatives such as 8-hydroxy cyclic AMP and 8-isopropylthio cyclic AMP, which were less susceptible to phosphodiesterase action, also effectively stimulated steroidogenesis. The uptake and metabolism of cyclic [(3)H]AMP in ovarian cells was also studied in relation to steroidogenesis. When ovarian cells were incubated for 2h in the presence of increasing concentrations of cyclic [(3)H]AMP, the radioactivity associated with the cells increased almost linearly up to 250mum-cyclic [(3)H]AMP concentration in the incubation medium. The (3)H label in the cellular extract was recovered mainly in the forms ATP, ADP, AMP, adenosine and inosine, with cyclic AMP accounting for less than 1% of the total tissue radioactivity. Incubation of cyclic AMP in vitro with ovarian cells resulted in a rapid breakdown of the nucleotide in the medium. The degradation products in the medium have been identified as AMP, adenosine and inosine. The rapid degradation of cyclic AMP by phosphodiesterase(s) makes it difficult to correlate changes in cyclic AMP concentrations with steroidogenesis. These observations thus provide an explanation for the previously observed lack of cyclic AMP accumulation under conditions in which low doses of choriogonadotropin stimulated steroidogenesis without any detectable changes in cyclic AMP accumulation.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗

PubMed1975

Ovulation induction: ovarian response to human gonadotropins and synthetic gonadotropin-releasing hormone.

Human ovarian responses to FSH- and LH-releasing hormone (FSH/LH-RH) were observed at laparotomy and studies by histologic and histochemical examination of ovarian biopsy specimens. The responses were compared to those induced by human menopausal gonadotropin (HMG) and human chorionic gonadotropin (HCG) singly and together. The subjects were healthy, fertile, young women rendered anovulatory by injections of depomedroxyprogesterone acetate (DMPA) or depochlormadinone acetate (CA). Supplementary studies included measurement of urinary pregnanediol, examination of the cervix and vagina for estrogenic and progestational responses, and endometrial biopsy, Both HMG and HCG induced follicular growth and proliferation of granulosa and theca cells, but neither, when given alone, induced ovulation or corpus luteum formation. When given in conjunction they induced single or multiple ovulations and corpora lutea in 11 of 18 women treated. FSH/LH-RH CONSISTENTLY STIMULATED FOLLICULAR DEVELOPMENT AND INDUCED OVULATION IN 2 OF 16 WOMEN TREATED. Preovulatory mature follicles were found in 3 more. FSH/LH-RH may prove to be useful in the treatment of some cases of anovulatory sterility of hypothalamic origin.

Adult↗

PubMed1978

Developmental changes in testicular gonadotropin receptors: plasma gonadotropins and plasma testosterone in the rat.

The relationships between plasma gonadotropins, testicular gonadotropin receptors, and plasma testosterone were examined during neonatal life and throughout sexual maturation in the rat. The binding affinity of testicular LH receptors (2.4 X 10(10) M-1) was significantly higher than that of FSH receptors (2.1 X 10(9) M-1) at all stages of development. The concentration of FSH receptors in the testis reached a peak between 10-15 days of age, then fell to a constant level from 25-90 days. However, the testis content of FSH receptors increased continually with age and reached a plateau at day 60. Plasma FSH declined after birth to a nadir at 15 days, then rose rapidly to a peak at day 38, and fell to a plateau from day 50 through adult life. In contrast to the rapidly changing profile of plasma FSH during early maturation, alterations in plasma LH were less marked throughout development. Although a progressive rise in plasma LH concentration was observed between days 36-51, the simultaneous changes in testicular LH receptors and plasma testosterone were much more prominent. Testicular LH receptors showed a continuous increase in concentration and total number with advancing age and testis growth. The major rise in LH receptor concentration occurred between 15-38 days age, at the same time as the rise in plasma FSH concentration and the phase of rapid testicular growth. Plasma testosterone fell during the 8th-24th days after birth, then rose rapidly between days 35-55. The pubertal rise in plasma testosterone occurred about 15 days after testicular LH receptors began to increase and was coincident with the continuing rise in LH receptor content from day 35 until day 55 and with the progressive increase in plasma LH during this period. These observations have demonstrated that the early development of testicular FSH receptors in followed by a prominent rise in plasma FSH, with concomitant increases in testicular growth and LH receptor concentration. The resulting increase in gonadal sensitivity to LH could be responsible for the marked increase in secretion of testosterone which occurs during puberty in the presence of a relatively small change in the circulating LH concentration. The sequence of changes observed in gonadotropins and their testicular receptors is consistent with the view that FSH-induced testicular sensitivity to LH is an important factor in sexual maturation in the male rat.

Aging↗

PubMed1976

Effect of gonadotropin-releasing hormone and human chorionic gonadotropin on cows with ovarian follicular cysts.

Ovarian follicular cysts of cattle were defined as follicular structures (larger than or equal to 2.5 cm, diameter) which persisted for 10 days or longer in the absence of functional luteal tissue. Thirty dairy cows with ovarian follicular cysts were allotted to 6 groups (5 cows per group) and each was given 0 (saline solution), 25, 50, 100, 150, or 250 mug of gonadotropin-releasing hormone (GnRH) by intramuscular (IM) injection. Samples of blood were collected before GnRH was injected (0 hour), at 0.25, 0.50, 0.75, 1, 2, 3, and 4 hours, and at 1, 7, 11, 15, and 20 days after treatment. Five additional cows with follicular cysts were treated IM with 10,000 units of human chorionic gonadotropin (HCG), and blood sample collections were made before treatment (0 hour) and on days 1, 7, 11, 15, and 20 after treatment. Serum luteinizing hormone (LH) concentration was not altered in cows given saline solution, but was increased significantly in cows given any of the doses of GnRH (in a dose-related manner). Peak LH responses occurred about 2 hours after GnRH was given, and by 4 hours LH was beginning to decrease. Serum progesterone concentrations increased by more than 2.0 ng/ml by day 11 after treatment in 18 of 20 cows treated with 50, 100, 150, or 250 mug of GnRH. Progesterone responses in these cows were greater (P less than 0.05) than in cows given saline solution or a 25-mug dose of GnRH. Mean progesterone response to the 4 large doses of GnRH was similar in magnitude and duration to serum progesterone changes during the leutal phase of the bovine estrous cycle. After cows were treated with HCG, serum progesterone values were similar to those in cows given GnRH (50 to 250 mug).

Animals↗

PubMed1978

Hormonal and clinical responses in amenorrhetic patients treated with gonadotropins and a nasal form of synthetic gonadotropin-releasing hormone.

Synthetic gonadotropin-releasing hormone (GnRH) in the form of nasal drops was self-administered by five amenorrheic patients in an attempt to assess its therapeutic value in anovulatory infertility. After follicular maturation had been induced with human menopausal gonadotropins (HMG), a total daily dose of 7.5 mg of GnRH in the form of nasal drops was self-administered at 2-hour intervals for 6 hours on 3 consecutive days. In four patients, plasma luteinizing hormone (LH) levels were significantly elevated over a period of at least 8 hours. In three of these patients, in addition, there was a definite upward shift in the basal body temperature (BBT) curve, and uterine bleeding occurred 6 to 9 days after the first dose of GnRH. In the fourth patient, ovulation was induced as indicated by a biphasic BBT curve, a plasma progesterone level of 13 ng/ml, and a luteal phase of 15 days. In the remaining patient, there was a borderline LH response and no clinical response. It is concluded that GnRH, in the form of nasal drops, is effective in eliciting and maintaining elevated plasma LH levels in patients in whom follicular maturation has been induced with HMG. By obtaining ovulatory LH levels, such a regimen can lead to ovulation. In addition, intranasal self-administration of GnRH is convenient and may provide an alternative route of administration for long-term therapy with this hormone.

Administration, Intranasal↗