Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is well established that the central alpha 2-adrenergic agonist clonidine can enhance growth hormone (GH) secretion in humans. This effect is most likely due to stimulation of hypothalamic growth hormone releasing hormone (GHRH) release. To determine the potency of the new I1-imidazoline receptor agonist moxonidine to release pituitary hormones, 12 normal volunteers received clonidine (0.3 mg), moxonidine (0.3 mg), or placebo orally according to a randomized, double-blind protocol. Blood was drawn prior and up to 180 min after drug administration for determination of GH, adrenocorticotropic hormone (ACTH), prolactin, thyrotropin (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), glucose, clonidine, and moxonidine concentrations. The results were compared to those obtained in a standard GHRH stimulation test (1 microgram/kg i.v.). Serum GH levels increased significantly in response to GHRH, clonidine, and moxonidine. However, the increase was less pronounced in response to clonidine and moxonidine as compared to GHRH (mean +/- SEM): after clonidine, GH increased from 0.2 +/- 0.1 to 5.4 +/- 1.5 ng/ml, p < 0.05; moxonidine increased GH levels from 0.1 +/- 0.04 to 4.8 +/- 1.9 ng/ml (p < 0.05); GHRH caused an increase from 0.01 +/- 0.05 to 14.8 +/- 2.5 ng/ml (p < 0.05). No significant change was observed in the concentration of any other pituitary hormone. We conclude that the new I1-imidazoline receptor agonist moxonidine stimulates GH release to a similar extent as clonidine.
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PMID:Growth hormone secretion in response to the new centrally acting antihypertensive agent moxonidine in normal human subjects: comparison to clonidine and GHRH. 758 24

Blood plasma concentrations of alpha-melanocyte-stimulating hormone (alpha-MSH), beta-endorphin (beta-END), prolactin and follicle-stimulating hormone (FSH), and associated changes in the size of the testes, and growth of the horns and pelage were measured in male (n = 8), castrated male (n = 5) and female (n = 9) Soay sheep. The animals were born in April and kept outdoors near Edinburgh (56 degrees N) during the first two years of life. In all groups there was a close association between the weekly changes in the plasma concentrations of alpha-MSH and beta-END; the molar ratio in mean concentrations was close to 1:1. The blood plasma concentrations of both hormones varied markedly with season with a 3- to 10-fold increase in concentrations from the minimum in winter to the maximum in autumn. The seasonal peak occurred in September in the first year of life as juveniles, and between July (males) and September (females) in the second year when the animals were sexually mature. The plasma concentrations of ACTH did not vary in parallel with the seasonal changes in the concentrations of alpha-MSH (measured only in males); the molar ratio for the concentrations of alpha-MSH:ACTH was 1:0.12. The seasonal increase in the concentrations of alpha-MSH occurred 1-3 months after the seasonal increase in the concentrations of prolactin and the associated growth in horns and pelage, and slightly before, or coincident with the seasonal increase in the concentrations of FSH and the growth in the testes. In a second experiment, the same parameters were measured in a group of adult male Soay sheep (n = 8) housed indoors under an artificial lighting regimen of alternating 16-week periods of long (16 h light: 8 h darkness) and short days (8 h light: 16 h darkness). In this situation, there was a clearly defined photoperiod-induced cycle in the plasma concentrations of alpha-MSH with a 25-fold increase from a minimum under long days to a maximum under short days. The concentrations of beta-END varied in close parallel with the changes in alpha-MSH, and the temporal associations with the changes in the other pituitary hormones were similar to those observed in animals housed outdoors. Overall, the results support the view that alpha-MSH is co-secreted with beta-END from the melanotrophs in the pars intermedia of the pituitary gland, and that the secretory activity of the melanotrophs changes markedly with season, increasing in summer and autumn, and decreasing in winter and spring.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Seasonal and photoperiod-induced changes in the secretion of alpha-melanocyte-stimulating hormone in Soay sheep: temporal relationships with changes in beta-endorphin, prolactin, follicle-stimulating hormone, activity of the gonads and growth of wool and horns. 773 72

We used 35S-labeled oligonucleotides and cRNAs (riboprobes) to detect the temporal order and spatial pattern of anterior pituitary hormone gene expression in (B6CBF1 x B6CBF1)F2 fetal mice from embryonic Day 9.5 (E9.5) to postnatal Day 1 (P1). Pro-opiomelanocortin (POMC) mRNA was expressed in the basal diencephalon on Day E10.5, in the ventromedial zone of the pars distalis on Day E12.5, and in the pars intermedia on Day E14.5. The common alpha-glycoprotein subunit (alpha-GSU) mRNA first appeared in the anterior wall of Rathke's pouch on Day E11.5 and extended to the pars tuberalis and ventromedial zone of the pars distalis on Day E12.5. Thyroid-stimulating hormone-beta (TSH beta) subunit mRNA was expressed initially in both the pas tuberalis and ventromedial pars distalis on Day E14.5, with an identical spatial distribution to alpha-GSU at the time. In contrast, luteinizing hormone-beta (LH beta) subunit and follicle-stimulating hormone beta (FSH beta) subunit mRNAs were detected initially only in the ventromedial pars distalis on Days E16.5 and E17.5, respectively, in an identical distribution to each other. POMC-, alpha-GSU-, TSH beta, LH beta-, and FSH beta-positive cells within the pars distalis all increased in number and autoradiographic signal with differing degrees of spatial expansion posteriorly, laterally, and dorsally up to Day P1. POMC expression was typically the most intense and extended circumferentially to include the entire lateral and dorsal surfaces of the pars distalis. The expression of both growth hormone (GH) and prolactin (PRL) started coincidentally on Day E15.5. However PRL cells localized in the ventromedial area similarly to POMC and the glycoprotein hormone subunits, whereas GH cells were found initially in a more lateral and central distribution within the lobes of the pars distalis. Somatotrophs increased dramatically in number and autoradiographic signal, extending throughout the pars distalis except for the most peripheral layer of cells on Day E17.5. Mammotrophs also increased in number but less abundantly than somatotrophs, and PRL expression remained more confined to central-medial and ventrolateral areas of the pars distalis up to Day P1. These data demonstrate distinctive patterns of expression for each of the major anterior pituitary hormone genes during development of the mouse pituitary gland and suggest that different groups of committed cells are the immediate precursors to the terminally differentiated hormone-secreting cell types.
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PMID:In situ hybridization analysis of anterior pituitary hormone gene expression during fetal mouse development. 802 30

Availability of recombinant growth hormone (GH) and development of long-acting formulations of this material will undoubtedly lead to widespread use of GH in animal industry and in medicine. GH can act, directly or indirectly, on multiple targets, but its influence on the reproductive system and on the hormonal control of reproduction is poorly understood. Overexpression of GH genes in transgenic animals provides a unique opportunity to study the effects of long-term GH excess. Transgenic mice overexpressing bovine, ovine, or rat GH (hormones with actions closely resembling, if not identical to, those of endogenous [mouse] GH), exhibit enhancement of growth, increased adult body size, and reduced life-span as well as a number of endocrine and reproductive abnormalities. Ectopic overexpression of bovine GH (bGH) driven by metallothionein or phosphoenolpyruvate carboxykinase promoters is associated with altered activity of hypothalamic neurons which produce somatostatin, loss of adenohypophyseal GH releasing hormone (GHRH) receptors, and suppression of endogenous (mouse) GH release. Elevation of plasma levels of GH (primarily bGH) and insulin-like growth factor (IGF-I) in these transgenic mice leads to increases in the number of hepatic GH and prolactin (PRL) receptors, in the serum levels of GH-binding protein (GHBP), in the percent of GHBP complexed with GH, and in the circulating insulin levels. In addition, plasma adrenocorticotropic hormone (ACTH) and corticosterone levels are elevated. Plasma levels of luteinizing hormone (LH), as well as its synthesis and release, are not consistently affected, but follicle-stimulating hormone (FSH) levels are suppressed, apparently due to pre- and post-translational effects. Pituitary lactotrophs exhibit characteristics of chronic enhancement of secretory activity, and plasma PRL levels are elevated. Prolactin responses to mating or to pharmacological blockade of dopamine synthesis are abnormal. Reproductive life span and efficiency are reduced in both sexes, with the severity and frequency of reproductive deficits being related to plasma bGH levels. Most transgenic females expressing high levels of bGH are sterile due to luteal failure. Overexpression of human GH which, in the mouse, interacts with both GH and PRL receptors leads to additional endocrine and reproductive abnormalities including stimulation of LH beta mRNA levels and LH secretion, loss of responsiveness to testosterone feedback, overstimulation of mammary glands, enhanced mammary tumorigenesis, and hypertrophy of accessory reproductive glands in males.
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PMID:Neuroendocrine and reproductive consequences of overexpression of growth hormone in transgenic mice. 807 44

The aim of this study was to assess the usefulness of ketoconazole as a therapeutic alternative to polycystic ovary syndrome. The study group comprised 37 women with signs of hyperandrogenism (hirsutism, acne) and oligomenorrhea. A low dose (400 mg/day) of ketoconazole was tested in a 9-month prospective clinical study. Clinical response (Ferriman & Gallway score, acne) and modifications in hormone pattern (luteinizing hormone, follicle-stimulating hormone, estradiol, testosterone, prolactin, 17-hydroxy-progesterone, androstenedione, steroid hormone-binding globulin, dehydroepiandrosterone sulfate, cortisol, adrenocorticotropin (ACTH) and free testesterone index) were measured, and ACTH stimulation tests were performed. Tolerance and side-effect also were assessed. After 9 months of ketoconazole treatment, the patients' Ferriman & Gallway scores (18.26 +/- 4.6 vs 12.4 +/- 4.1; p < 0.001) and acne had improved markedly. Hormone patterns also became more favorable, with decreases in androgenic steroids (testosterone, androstenedione, free testosterone index and dehydroepiandrosterone sulfate; p < 0.01) and increases in estradiol (p < 0.01). Basal cortisol levels and cortisol after ACTH stimulation were not changed significantly, remaining within the reference range. Increases in ACTH were observed only in the 3rd month (p < 0.01). Initial levels of androgenic steroids were correlated inversely with their percentage decrease in successive samplings. Decreases in adrenal androgenic steroids were associated with an increase in steroid hormone-binding globulin. The side-effects of treatment, although not severe, caused some discomfort and led to a high drop-out rate (30%).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Ketoconazole therapy: hormonal and clinical effects in non-tumoral hyperandrogenism. 816 60

A 40-year-old Black man presenting with increasing nasal discharge of bloody, mucoid pus as well as nasal obstruction over a 2-month period is described. Magnetic resonance imaging of the skull showed a tumor eroding through the skull base into the clivus and extending into the sphenoid sinus. Endoscopy of the sphenoid sinus demonstrated a polypoid mass extending into the posterior choanae. The lesion was partially resected. Histologic evaluation showed a cellular small blue cell tumor punctuated by bland, epithelial-lined microcysts. Electron microscopy revealed epithelial cells with abundant rough endoplasmic reticulum and electron-dense membrane-bound endocrine granules, some undergoing misplaced exocytosis. Immunohistochemical evaluation demonstrated cytoplasmic reactivity for neuron-specific enolase, synaptophysin, and prolactin. Stains for leukocyte common antigen, HMB-45, desmin, cytokeratin, chromogranin, and the remaining spectrum of pituitary hormones including growth hormone, corticotropin, luteinizing hormone, follicle-stimulating hormone, and thyrotrophic hormone were negative. In contrast, the epithelium lining the cysts was cytokeratin positive and synaptophysin negative. This ostensibly small cell tumor therefore represented a remarkably extensive and aggressive prolactin cell adenoma with unusual light microscopic features. Characterization of the lesion required electron microscopy and further confirmation by immunocytology. The distinction of pituitary adenomas and particularly of prolactin cell tumors from other adenoma types and from other small cell lesions markedly affects therapy and patient prognosis.
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PMID:Aggressive small cell tumor of the skull base. 819 26

The rdw rat (gene symbol: rdw) with hereditary dwarfism has been shown immunohistochemically to have subnormal numbers not only of GH- but also of prolactin- and thyrotrophin-positive cells. To characterize the dwarfism of this strain, the expression of pituitary hormone mRNAs was examined by Northern hybridization. The pituitary gland in the rdw rat expressed 30-100 times less GH and prolactin mRNAs than normal controls, whereas mRNAs for pro-opiomelanocortin and the alpha subunit of rat glycoprotein hormone revealed a significant increase. There was a non-significant difference in rat LH-beta subunit and FSH-beta subunit between normal and rdw rats. The suppressed expression of a pituitary-specific transcription factor, Pit-1, is considered to cause hereditary dwarfism in mouse strains Snell and Jackson, whose phenotypes resemble those of the rdw rat. In this study, however, no difference in mRNA expression for Pit-1 was found between rdw rats and controls. This work indicates that the rdw rat may not have the same genotype as the phenotypically similar dwarf mice, Snell, Jackson and Ames.
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PMID:Expression of mRNA coding for pituitary hormones and pituitary-specific transcription factor in the pituitary gland of the rdw rat with hereditary dwarfism. 822 39

Clinico-pathological correlations in horses with pituitary adenomas are poorly understood. This paper describes the functional and morphological features of five cases of equine pituitary adenoma and of a case of multinodular pituitary hyperplasia. New findings reported include immunoreactivity for beta-lipotropin (beta-LPH), beta-melanocyte-stimulating hormone (beta-MSH), gamma 3-MSH, prolactin (PRL), and follicle-stimulating hormone (FSH) in neoplastic cells of the pituitary adenoma; and, in the multinodular hyperplasia, beta-LPH, beta-endorphin (beta-END), alpha-MSH, beta-MSH, gamma 3-MSH and FSH immunoreactivity. It is suggested that the equine pituitary syndrome does not correspond to human Cushing's disease, as generally accepted, but is related to the overproduction of several pro-opiomelanocortin (POMC)-derived peptides by the cells of the tumour or hyperplastic nodules.
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PMID:Equine pituitary adenoma: a functional and morphological study. 824 32

The presence of glucocorticoid receptor (GR) in the anterior lobe of the pituitary gland has previously been demonstrated, but the exact cell types expressing GR have not yet been characterized. In this study, we demonstrate the colocalization of GR and pituitary hormones in the rat pituitary gland by using an immunocytochemical double-labelling method. The majority of anterior lobe corticotropin-immunoreactive and growth hormone-immunoreactive cells contained GR-like immunoreactivity. Cells of the intermediate lobe showed intensive ACTH-like immunoreactivity but did not express GR. The glycoprotein hormones thyroid-stimulating hormone, follicle-stimulating hormone and luteinizing hormone were colocalized with GR to a lesser degree; approximately one-half of the cells exhibited immunoreactivity to these hormones contained GR. By contrast, only a minority of the prolactin-immunoreactive cells expressed GR. Our results suggest that glucocorticoids may differentially regulate the secretion and/or synthesis of these pituitary hormones by directly affecting the hormone-producing cells of the anterior pituitary.
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PMID:Glucocorticoid receptor colocalization with pituitary hormones in the rat pituitary gland. 831 36

This study investigated the direct effects of hydrocortisone (HS), corticotropin-releasing factor (CRF), and adrenocorticotropin (ACTH) on basal and gonadotropin-releasing hormone (GnRH)-stimulated secretion of follicle-stimulating hormone (FSH) from dispersed pig pituitary cells in vitro. Pig pituitaries were dispersed into cells with collagenase, DNAase, and hyaluronidase and then cultured in McCoy's 5a medium containing horse serum (10%) and fetal calf serum (2.5%) pretreated with dextran-coated charcoal for 3 days. Cells were preincubated with steroids, CRF, or ACTH before GnRH was added. HS did not affect basal FSH secretion after 72 h of incubation. Treatment of pituitary cells with increasing concentrations (0.001-800 micrograms/ml) of HS for 72 h resulted in a dose-dependent decrease in GnRH-stimulated FSH release. HS pretreatment did not cause a change in cellular FSH content. Increasing duration (6-72 h) of treatment with HS (200 micrograms/ml) led to a time-dependent decrease in GnRH-stimulated FSH release, achieving statistical significance by 12 h. Porcine ACTH had no influence on basal and GnRH-stimulated FSH secretion. CRF decreased GnRH-stimulated FSH secretion in a dose-dependent manner, and the inhibitory effect required preincubation (6-18 h) with CRF. HS inhibited the FSH secretory responses to phospholipase C, melittin, and 8-bromo-cAMP but did not affect the response to 1,2-dioctanoyl-sn-glycerol and ionophore A23187. These results indicate that both cortisol and CRF can act directly on pig pituitary to inhibit FSH responsiveness to GnRH.
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PMID:Actions of corticotropin-releasing factor or cortisol on follicle-stimulating hormone secretion by isolated pig pituitary cells. 839 May 96


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