Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this study was to investigate the importance of inhibin in the delay in return to oestrus in heifers induced by steroid-stripped bovine follicular fluid (bFF). Oestrous activity was synchronized in 18 Hereford x Friesian heifers with two injections of prostaglandin (PG) 12 days apart. At the time of the second PG injection (time 0), the animals were assigned at random to one of three experimental groups and received i.v. injections of 20 ml saline (controls, n = 6), whole bFF (FF group, n = 6) or bFF in which the bioactive inhibin content had been reduced by > 95% by immunoaffinity chromatography (-INH group, n = 6; inhibin content approximately 0.8 ml whole bFF) every 8 h for 2 days. In a dose-response study, 2.5 ml whole bFF was insufficient to delay oestrus consistently following a similar synchronization regimen. Blood samples were taken every 8 h, initially before each injection and then subsequently for a further 9 days for hormone analysis. Animals were observed every 8 h throughout the experiment for signs of behavioural oestrus. The ovaries of all animals were examined using real-time ultrasonography about 30 h after the second PG injection. Treatment failed to suppress peripheral follicle-stimulating hormone (FSH) concentrations, although a significant increase was observed in both treatment groups after cessation of injections. Progesterone concentrations fell immediately after the second PG injection in all animals and remained below minimum detectable concentrations in all treated animals for the remainder of the experiment. In control animals, progesterone rose above minimum detectable concentrations by day 6 and continued to rise until the end of the experiment. Analysis of samples taken from treated animals several days after observed oestrus revealed that all had apparently ovulated. Mean daily luteinizing hormone (LH) concentrations did not differ between treatment groups before ovulation, but after ovulation, mean daily LH was significantly reduced in control animals as progesterone concentrations rose. Follicular development, as assessed by the mean antral diameter of the largest follicle on a pair of ovaries at ultrasound examination, was significantly suppressed in treated animals compared with controls (P < 0.01) and there was no significant difference (P = 0.397) between the two treatment groups. Control animals displayed oestrus 68 h (+/- 8 SEM) after the second PG injection, but oestrus was delayed in treated animals to 186h +/- 5 (FF group) and 191 h +/- 6 (-INH group).
 ...
PMID:Evidence for the action of bovine follicular fluid factor(s) other than inhibin in suppressing follicular development and delaying oestrus in heifers. 133 40

Forty-two Scottish Blackface ewes that lambed outdoors in March were removed from their lambs at the end of April and housed under natural daylength at 57 degrees N. Treatments (n = 7 ewes per treatment) commenced on 1 May and comprised daily oral dosing at 15:00 h with 3 mg melatonin dissolved in water and ethanol (4:1, v/v) for 30, 60, 90, 120 or 150 days. Control ewes received the vehicle alone. Ovarian activity was assessed by laparoscopy at monthly intervals with an additional interim observation in mid-July. Blood was sampled three times a week by jugular venepuncture and assayed for progesterone, prolactin and follicle-stimulating hormone (FSH). Luteinizing hormone (LH) was determined in blood samples collected at 15 min intervals for 10 h on days 28, 60, 91, 119 and 150. Thirty days of melatonin treatment delayed (P < 0.01) first ovulation by about 1 month (mean interval +/- SEM from 1 May to progesterone > 1 ng ml-1, 165 +/- 4.5 days versus 132 +/- 9.2 days for controls). None of the ewes that received melatonin for 60 days ovulated before the end of melatonin treatment, but subsequently six of them did; the mean interval from 1 May to increased progesterone concentration was 75 +/- 1.2 days. All ewes receiving melatonin for 90, 120 and 150 days ovulated with corresponding mean intervals of 83 +/- 2.7, 85 +/- 1.3 and 87 +/- 2.2 days, respectively (P < 0.001 compared with controls).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effect of duration of melatonin treatment on the onset and duration of oestrous cyclicity in ewes. 140 88

In mares, the amount of gonadotrophin-releasing hormone (GnRH) is low in the hypothalamus during seasonal anoestrus, but by early spring, concentrations of GnRH are high. The timing of this response was characterized more precisely by determining concentrations of GnRH in hypothalamic tissue collected immediately before and at various times after the winter solstice (22 December 1986). Ovaries, pituitary gland, hypothalamus and a blood sample were collected from six groups of mares (6-12 mares per group) at death, 1 week before day of the winter solstice and 1, 2, 3 and 12 weeks afterwards. No significant changes in weight of the anterior pituitary gland or concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were observed in the anterior pituitary gland (P > 0.1). Mean diameter of the largest follicle, number of follicles > or = 20 mm in diameter and concentrations of LH and FSH in serum remained unchanged for weeks -1 to +3 (P < 0.05), then increased significantly by week 12 (P < 0.001). Content and concentration of GnRH in the median eminence was low at -1 week, increased gradually (P < 0.05) to a maximum by +1 week, then decreased gradually (P < 0.05) to low values at 12 weeks. Means (+/- SEM) for -1, +1 and +12 weeks were 33.5 +/- 5.5, 117.7 +/- 18.6 and 29.8 +/- 3.7 ng GnRH, respectively. Mean content of GnRH in the preoptic area of the hypothalamus showed a reciprocal pattern.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Changes in the hypothalamic-hypophyseal axis of mares in relation to the winter solstice. 143 50

The timing of ovulation relative to the onset of oestrus and the preovulatory surge in luteinizing hormone (LH) was studied in red deer following treatments to synchronize oestrus and induce either a monovulatory or superovulatory response. Mature hinds (n = 36) were allocated randomly to two mating groups (n = 16 + 20), with respective treatments staggered by 4 weeks during the 1990 rut (March-April). Each hind was treated with an intravaginal controlled internal drug releasing (CIDR)-type S device for 14 days. Treatments to induce a monovulatory response included CIDR device alone (treatment A; n = 4 + 8) and additional injection of 200 iu pregnant mares' serum gonadotrophin (PMSG) at device removal (treatment B; n = 4 + 4). Treatments to induce a superovulatory response included injections of 200 iu PMSG and 0.5 units ovine follicle-stimulating hormone (FSH) at about time of removal of CIDR devices (treatment C; n = 4 + 4) and further treatment with gonadotrophin-releasing hormone (GnRH) analogue 18 h after removal of CIDR devices (treatment D; n = 4 + 4). The hinds were run with crayon-harnessed stags from insertion of CIDR devices (12 March or 9 April) and blood samples were taken every second day to determine plasma progesterone. Further blood samples were collected for determination of plasma LH and progesterone via indwelling jugular cannulae every 2 h for 72 h from removal of CIDR devices. Hinds were allocated randomly to an initial ovarian examination by laparoscopy at either 16 or 20 h (A and B), or 12 or 16 h (C and D) after the onset of oestrus, with laparoscopy repeated at intervals of 8 h until either ovulation was recorded (A and B), or for four successive occasions (C and D). All hinds received cloprostenol injections 15 days after device removal. A total of 28 hinds (78%) exhibited oestrus and a preovulatory LH surge, with mean (+/- SEM) times to onset of oestrus of 44.6 +/- 1.0 h (A; n = 7), 37.4 +/- 2.0 h (B; n = 7), 16.3 +/- 1.7 h (C; n = 6) or 14.0 +/- 1.7 h (D; n = 8). Failure to exhibit oestrus or LH surge was most prevalent among hinds in treatment A early in the rut.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Relationship between the onset of oestrus, the preovulatory surge in luteinizing hormone and ovulation following oestrous synchronization and superovulation of farmed red deer (Cervus elaphus). 143 58

Macroprolactinomas have been well documented in men over the past several years. By contrast, to the best of our knowledge, there have been no reports of microprolactinomas in men. We describe here 14 cases of microprolactinomas occurring in male patients (14 to 53 years old) and discovered on the basis of endocrine symptoms. Nine patients complained of impotence and/or decreased libido, 8 had gynecomastia with or without galactorrhea, 1 had undergone incomplete puberty. All patients had hyperprolactinemia (225 +/- 65 micrograms/l, mean +/- SEM, N less than 13 micrograms/l); plasma testosterone levels were low in 9 (162 +/- 33 ng/dl, mean +/- SEM; N = 308 - 876 ng/dl), while plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels and their responses to LH-releasing hormone (LHRH) were normal in all cases. Among the 14 patients, 12 had no hypopituitarism and 2 had only partial corticotrope insufficiency; none had visual disturbances and only one complained of headaches. The sella turcica was normal in size and shape in 2 cases but a double floor and/or a thinner part of the floor was observed in 12. CT scan of MRI demonstrated in all cases an intrasellar microadenoma with a mean size of 7 mm (range, 3 to 10 mm) and no preferential localization. One patient was treated with bromocriptine, while the others underwent surgery via the transsphenoidal route. Immunocytochemistry demonstrated immunoreactive-prolactin (IR-PRL) cells in all the adenomas. Surgery resulted in normalization of plasma PRL in 11 of the 13 patients and in lowering PRL levels in the others 2.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Prolactin microadenoma in men. Study of 14 cases]. 153 Feb 27

From preclimacteric women (n = 10, 45-50 years of age) with gross cystic breast disease, levels of beta-endorphin, estradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, cortisol and prolactin were assayed radiochemically in the breast cyst fluid and in plasma. The beta-endorphin concentration (fmol/ml) was increased more than fourfold in the breast cyst fluid (17.6 +/- 4.6 SEM) than in plasma (4.2 +/- 0.5 SEM). In the breast cyst fluid, estradiol was increased 41-fold (1738.2 +/- 350.5 SEM pg/ml), and progesterone 47-fold (65.47 +/- 8.25 SEM ng/ml) more than in plasma. The significantly increased values of beta-endorphin, estradiol and progesterone in the breast cyst fluid and the identification of beta-endorphin in cyst-lining epithelia demonstrate the local synthesis. Growth factor-like properties of beta-endorphin and estradiol are accountable for the propagation of cystic changes. The autonomic formation and function of beta-endorphin, estradiol and progesterone in cyst compartments can not be related with the levels of luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone and cortisol, which were significantly higher in plasma than in the breast cyst fluid. In the breast cyst fluid, prolactin could not detected to be significantly higher than in plasma. In addition the plasma-concentration of testosterone, androstenedione, thyroxin, triiodothyronine, thyroid-binding globulin, sexual-hormone-binding-globulin could be detected within the normal range. In this study we could demonstrate the synergism of beta-endorphin, steroid hormones and peptide hormones which advance the growth of gross cystic disease of preclimacteric women. Beta-endorphin was also examined by immunocytochemical assays (fluorescence, alkaline phosphatase and horseradish peroxidase method), in 11 women with pure fibrocystic disease, in 7 women with fibrocystic disease combined with a carcinoma in situ and in 15 women with fibrocystic disease combined with invasive carcinoma of the breast. Sections of frozen and paraffin embedded tissue of the same patient were reacted with anti-beta-endorphin antiserum. The immunoreactivity of beta-endorphin was intense in normal, proliferative altered and cyst-lining epithelia of fibrocystic disease and decreased in atypical epithelia and carcinoma cells of the breast. The degree of beta-endorphin staining is related to the degree of cell differentiation. In addition, nuclear receptors for estrogen and progesterone were assayed by peroxidase antiperoxidase technique.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:[Interaction between beta-endorphin, steroids and peptide hormones in fibrocystic lesions of the female breast]. 164 46

Girls suffering from idiopathic central precocious puberty (CPP) may have different levels of estrogenic activity. This study was performed to evaluate the relationship between the estrogenic activity and the hypothalamopituitary activation and the effect of various plasma estradiol (E2) levels on growth, skeletal maturation and plasma insulin-like growth factor I (IGF-I). Fifty-eight girls with CPP were divided into 2 groups: group I with E2 less than 25 pg/ml (13 +/- 1 pg/ml, mean +/- SEM, n = 26) and group II with E2 greater than or equal to 25 pg/ml (52 +/- 3 pg/ml, n = 32). The mean ages at onset and at evaluation were lower in group I (5.9 +/- 0.4 and 6.8 +/- 0.4 years) than in group II (6.8 +/- 0.3 and 8.1 +/- 0.2 years, p less than 0.01), but the durations since onset (greater than 0.5 and less than 2 years) in the two groups were similar. The mean peak luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratios were lower in group I (0.8 +/- 0.2) than in group II (1.7 +/- 0.2, p less than 0.001) and correlated with E2 (r = 0.41, p less than 0.01). The mean height gains during the year preceding the initial evaluation were similar in the two groups (8.7 +/- 0.5 vs. 9.2 +/- 0.4 cm). They were independent of the plasma E2 level. Conversely, the mean plasma IGF-I values were lower in group I (2.4 +/- 0.3 U/ml) than in group II (4.2 +/- 0.6 U/ml, p less than 0.01) and correlated with E2 (r = 0.52, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Idiopathic central precocious puberty in girls as a model of the effect of plasma estradiol level on growth, skeletal maturation and plasma insulin-like growth factor I. 181 7

To study the dose response characteristics of a gonadotropin-releasing hormone (GnRH) antagonist ([Ac-D2-Nal1,D4-Cl-Phe2,D3-Pal3,Arg5,dGlu6 (AA), d-Ala10] GnRH; Nal-Glu), 1.5 or 5.0 mg of Nal-Glu were administered to two groups of five normal men by daily subcutaneous injection for 21 days. Serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T) were determined on multiple occasions before, during, and after the antagonist treatment. Five milligrams Nal-Glu markedly suppressed mean serum immunoreactive LH to a mean of 1.5 +/- 0.4 IU/L (+/- SEM), immunoreactive FSH to the limit of assay detection (1 IU/L), and lowered basal mean serum T to castrate range (less than 2 nmol/L). Serum bioactive LH levels also showed a marked decrease in the 5.0-mg group similar to that seen in immunoreactive LH levels. Amplitude of immunoreactive LH pulses was markedly reduced in the 5.0-mg group on day 21. A 1.5-mg dose of Nal-Glu transiently suppressed serum immunoreactive LH levels on day 1. There was a subsequent escape on the rest of the days sampled. Serum immunoreactive FSH levels were not significantly changed over the 21-day treatment period. Serum T levels were transiently suppressed only on day 1 paralleling immunoreactive LH suppression. No adverse systemic side effects occurred. Thus, the 5.0-mg dose of this GnRH antagonist provides a pharmacological means of markedly suppressing the hypothalamic-pituitary-gonadal axis and, therefore, has potential as a male contraceptive.
 ...
PMID:Marked suppression of gonadotropins and testosterone by an antagonist analog of gonadotropin-releasing hormone in men. 189 88

The suppressive effect of the gonadotropin-releasing hormone (GnRH) antagonist Nal-Glu ([Ac-D2Nal1, D4ClPhe2, D3Pal3, Arg5, D-4-p-methoxybenzoyl-2-aminobutyric acid6, DAla10]-GnRH), injected intramuscularly with 5 mg, was studied in six men. Testosterone decreased by 87 +/- 2.3%, whereas the mean drops were 50 +/- 10%, 43 +/- 6.6%, and 39 +/- 5.6% for radioimmunoassayable luteinizing hormone (LH), follicle-stimulating hormone, and free alpha-subunit, respectively (mean +/- SEM). Immunological characteristics of plasma LH were modified during the inhibition and recovery phases as evidenced by comparison between polyclonal and monoclonal assays. In two additional subjects sampled every 10 minutes, both LH and alpha-subunit pulses were suppressed by NalGlu injection and restored by pulsatile GnRH infusion. However, a nonpulsatile and possibly non-GnRH-dependent alpha-subunit secretion was maintained after NalGlu administration.
 ...
PMID:Changes in gonadotropin and alpha-subunit secretion after a single administration of gonadotropin-releasing hormone antagonist in adult males. 211 79

Stage-specific binding of follicle-stimulating hormone (FSH) was measured in rat seminiferous tubules. The binding in single-point assays was over 3-fold higher (P less than 0.05) in stages XIII to I than in stages VI to VII of the epithelial cycle. No difference was found between the equilibrium association constants (Ka) of FSH binding in stages XIV to IV (10 +/- 1.9 X 10(9) 1/mol) and VII to VIII (9.2 +/- 0.6 X 10(9) 1/mol, mean +/- SEM, n = 5). In another experiment, the testes were dosed locally with 3 Gy of 4 MV x-irradiation to selectively lower the number of spermatogonia. After irradiation, FSH binding in staged seminiferous tubule segments was measured when the desired types of spermatogenic cells were reduced in number. Seven days after irradiation when differentiating spermatogonia and preleptotene spermatocytes were reduced in number, FSH binding was decreased in all stages of the cycle, but the cyclic variation remained. Seventeen days after irradiation when intermediate and type B spermatogonia and spermatocytes up to diplotene of stage XIII showed low numbers, FSH binding was decreased in all stages of the cycle and the stage-dependent variation disappeared. At 38 days when pachytene spermatocytes and early spermatids were reduced in number, similar results were found. But at 52 days postirradiation when all spermatids were low in number, FSH binding was slightly elevated compared with days 17 and 38. There were no significant differences in serum FSH or LH levels between irradiated and non-irradiated animals. These findings suggest that all spermatogenic cell types may stimulate FSH binding in the Sertoli cells.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Cellular regulation of follicle-stimulating hormone (FSH) binding in rat seminiferous tubules. 212 Jan 66


1 2 3 4 5 6 7 8 Next >>