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)

The authors conducted single- and double-blind studies of the responses of 7 chronic male schizophrenic patients to 10 mg of naloxone. BPRS ratings were made before and 6 hours after the injection; ACTH blood levels were determined before and 1 1/2 and 6 hours after injection. Statistically significant improvement of psychotic behavior occurred after 6 hours. The greatest improvement occurred in the patient who showed the most pronounced diurnal variation of ACTH levels, and there was no improvement in the patient who had no diurnal changes. Prolactin plasma levels following endorphin injections were apparently dose-dependent and peaked at approximately 30 minutes. The mean half-life of elimination of exogenous beta-endorphin was between 12 and 35 minutes. The authors theorize that positive and negative behavioral responses to naloxone depend--as possibly do many placebo responses in general--on the relative stress produced by experimental or therapeutic interventions.
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PMID:beta-Endorphin and naloxone in psychiatric patients: clinical and biological effects. 22 Aug 89

Hormones are necessary for the growth of mammary glands, for initiation of the secretory process, and for the maintenance of an established lactation in all mammals. Hormonal changes which occur in late pregnancy and the early postpartum period are described and graphed. This data was derived from research with animal models and relevant human data. Enzymatic and cytologic differentiation of the mammary gland and limited mammary secretion begin during late pregnancy. This constitutes the 1st stage of lactogenesis. The 2nd stage consists of a great increase in lactation secretion occurring 0-4 days before delivery. Quantities of milk produced are very variable. The role of all the following hormones in lactogenesis are described: prolactin; adrenocorticotropin (ACTH, which stimulates glucocorticoid secretion); estrogens; placental lactogens. Maintenance of intense lactation also depends on a complex of hormones. Prolactin seems to be the most important hormone at this stage of the process. Milk secretion continuation is reliant on constant milk removal.
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PMID:Endocrinology of lactation. 23 Jun

The ontogenesis of cells containing polypeptide hormones (ACTH, MSH, LPH, GH and Prolactin) was investigated in the fetal rat hypophysis by immunohistochemistry using the peroxidase-antiperoxidase complex. Corticotrophs, melanotrophs and lipotropic cells were revealed earlier in the pars distalis than in the pars intermedia. In the pars distalis, cells producing LPH were found in the morning of day 15 of gestation using anti-gamma- or anti-beta-LPH sera, and in afternoon using anti-alpha- or beta-endorphin sera. Cells containing beta-MSH were observed from the afternoon of day 15. The cells stainable with the anti-alpha-MSH, anti-beta-(17--39)ACTH and anti-beta-(1--24)ACTH sera appeared on day 16. In the pars intermedia, the cells producing alpha-MSH, beta-MSH, alpha- and beta-endorphin, gamma- and beta-LPH were observed in the morning of day 17, while cells containing ACTH were only revealed in the afternoon of the same day of gestation. Based on the treatment of serial paraffin sections with various antisera, it was clearly shown that MSH, ACTH, and LPH occur in the same cells located in the pars distalis as in the pars intermedia. The development of the corticotrophs, melanotrophs and lipotropic cells does not require the presence of the fetal hypothalamus or other central nervous structures. The pituitary glands of 21 day-old fetus encephalectomized on day 16 showed as many reactive cells as those of the littermate controls. The somatotrophs were first revealed in the pars distalis in the afternoon of day 19. The cells producing prolactin were not observed before day 21 of gestation. On some cases GH and prolactin were found together in one cell. The cytodifferentiation of GH and prolactin cells is apparently not under hypothalamic control.
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PMID:Ontogenesis of cells producing polypeptide hormones (ACTH, MSH, LPH, GH, prolactin) in the fetal hypophysis of the rat: influence of the hypothalamus. 37 82

Various drugs and hormones influence the light microscopic and especially the electron microscopic structure of the anterior pituitary and its tumors. Many structural effects are known only from animal experiments since specimens from human pituitaries are mostly not available. The structure of growth hormone (GH) cells is relatively stable. A massive GH cell hyperplasia is known only in rare cases with growth hormone releasing factor (GRF) excess from tumors. Prolactin cells can be stimulated by drugs, neurotransmitters, and hormones which decrease the dopamine inhibition. Adrenocorticotropic hormone (ACTH) cells are stimulated by stress, some hormones, loss of adrenals, and drugs which activate the alpha 1- and beta-receptors or inhibit the alpha 2-receptors. They are suppressed and changed into Crooke's cells by treatment with glucocorticoids. Thyroid-stimulating hormone (TSH) cells increase in number and size in states for overstimulation especially by thyrotropin releasing hormone (TRH). A decrease results from hyperthyroidism and possibly from somatostatin, L-dopa, and dopamine. Gonadotroph cells transform into castration cells in strongly hyperactive states (gonadectomy, antiandrogens, gonadotropin releasing hormone [Gn-RH]agonists, aminoglutethimide). Special types of pituitary adenomas can be treated with drugs which suppress hormone production and proliferation. Dopamine agonists and somatostatin reduce the tumor size of varying proportions of GH secreting adenomas in acromegaly. Ultrastructurally, a decrease of cytoplasmic and nuclear volume and an increase of lysosomes are found. Bromocriptine and other dopamine agonists are established in the treatment of prolactin secreting adenomas. They induce a shrinkage in many cases. Ultrastructurally, a reduction of cellular and nuclear size, an increase in number of secretory granules and of lysosomes, and a reduction of rough endoplasmic reticulum can be demonstrated.
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PMID:Effect of drugs on pituitary ultrastructure. 154 57

Prolactin (PRL) and alpha-melanocyte-stimulating hormone (alpha-MSH) are the only two pituitary hormones whose basal secretion is under tonic dopaminergic inhibition exerted by the hypothalamus. In the female rat, continuous exposure to estrogens is believed to depress hypothalamic dopaminergic activity and lead to the appearance of PRL-secreting pituitary adenomas during aging. Since there is no information about the impact of aging on circulating alpha-MSH levels, it was of interest to assess and compare the serum levels of PRL and alpha-MSH in male and female rats of different ages. Young (3-4 months) and old (24-25 months) male and female Sprague-Dawley rats as well as senescent (33-35 months) females were killed by decapitation between 10 AM and 1 PM, and pituitaries were immediately removed and dissected. Hormones were measured in unextracted trunk serum by radioimmunoassay. Serum PRL levels were (mean +/- SE), 18.4 +/- 2.0, 26.8 +/- 3.8, 19.8 +/- 2.5, 43.0 +/- 7.5, and 193.5 +/- 47.6 ng/ml for young and old males, and young, old, and senescent females, respectively. Serum alpha-MSH levels were 243.2 +/- 15.2, 252.9 +/- 24.8, 320.0 +/- 31.3, 234.7 +/- 19.1, and 374.0 +/- 29.7 pg/ml for young and old males, and young, old and senescent females, respectively. Anterior pituitary and neurointermediate lobe weights increased significantly with age in both sexes, although the change was particularly conspicuous in the females. We conclude that aging does not have a major impact on circulating alpha-MSH levels in rats and that melanotrophs probably have a greater ability than prolactotrophs to withstand age-associated alterations in central regulatory mechanisms.
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PMID:Differential effect of aging on serum levels of prolactin and alpha-melanotropin in rats. 184 77

Several monokines, proteins secreted by monocytes and macrophages, alter release of hormones from the anterior pituitary. We report here the ability of femtomolar concentrations of interleukin 2 (IL-2), a lymphokine released from T lymphocytes, to alter directly pituitary hormone release. The effects of concentrations of IL-2 ranging from 10(-17) to 10(-9) M on anterior pituitary hormone release were evaluated in vitro. Hemipituitaries were preincubated in 1 ml of Krebs-Ringer bicarbonate buffer (KRB) followed by incubation for 1 or 2 hr with KRB or KRB containing different concentrations of IL-2. This was followed by incubation for 30 min in 56 mM potassium medium to study the effect of pretreatment with IL-2 on subsequent depolarization-induced hormone release. Prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), corticotropin (ACTH), growth hormone (GH), and thyrotropic hormone (TSH) released into the incubation medium were measured by radioimmunoassay. IL-2 stimulated the basal release of PRL at 1 or 2 hr but suppressed the subsequent depolarization-induced PRL release, perhaps because the readily releasable pool of PRL was exhausted. The minimal effective dose (MED) was 10(-15) M. Conversely, IL-2 significantly suppressed the basal release of LH and FSH at 1 or 2 hr, with a MED of 10(-16) M, thus demonstrating a reciprocal action of the cytokine on lactotrophs and gonadotrophs. The subsequent depolarization-induced release of LH and FSH was suppressed, indicative of a persistent inhibitory action of IL-2. IL-2 stimulated ACTH and TSH release at 1 hr and the MEDs were 10(-12) and 10(-15) M, respectively. Conversely, IL-2 significantly lowered the basal release of GH at 1 hr, with a MED of 10(-15) M. The release of GH was not altered at 2 hr. The high potassium-induced release of ACTH, TSH, and GH was not affected. The results demonstrate that IL-2 at picomolar concentrations affects the release of anterior pituitary hormones. This cytokine may serve as an important messenger from lymphocytes exerting a direct paracrine action on the pituitary by its release from lymphocytes in the gland or concentrations in the blood that reach the gland may be sufficient to activate it.
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PMID:Anterior pituitary hormone control by interleukin 2. 184 83

Sequential exposure to stressors may elicit a period of endocrine hyperresponsiveness during which plasma hormone concentrations reach higher levels after repeated exposure to a stressor compared to levels after initial exposure. The present study was designed to further characterize hyperresponsiveness to repeated stress and determine if hyperresponsiveness is dependent upon repeated exposure to the same stressful stimuli. In Experiment 1, rats were stressed by inescapable tailshock, immobilization or exposure to shock chamber without shock for one, two, three, four or five consecutive days (15 min/day). In rats exposed to tailshock, corticosterone (CS) levels in plasma collected on days 2, 3, 4 and 5 were higher than CS levels following acute tailshock on day 1, demonstrating hyperresponsiveness to repeated tailshock. Hyperresponsiveness of CS secretion also occurred in groups of rats restrained for four or five days. No changes occurred in the CS response of animals repeatedly exposed to immobilization. Prolactin (PRL) levels were not affected by repeated exposure to the stressors. However, PRL values were different between the stress conditions and indicated that the order of stressor severity was tailshock greater than immobilization greater than exposure to shock chamber without shock. In Experiment 2, rats were exposed to either one or two consecutive days of tailshock or immobilization. Other rats were exposed to either tailshock or immobilization on the first day, then switched to the other stressor on the next day. Hyperresponsiveness to repeated tailshock, but not immobilization, was reflected in plasma levels of CS and adrenocorticotropic hormone (ACTH), but not PRL. Hyperresponsiveness of CS and ACTH secretion also was found in rats first stressed by immobilization then switched to tailshock, demonstrating that hyperresponsiveness is not dependent upon reexposure to familiar stressful stimuli. However, hyperresponsiveness did not occur in rats first exposed to tailshock then switched to immobilization. The data suggest that both immobilization and tailshock primed the organism to hyperrespond, but only the more severe stressor (tailshock) elicited hyperresponsiveness of the neuroendocrine system.
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PMID:Hyperresponsiveness of the rat neuroendocrine system due to repeated exposure to stress. 196

Prolactin (PRL) responds to several stimuli that elicit release of adrenocorticotropin (ACTH), but does not increase in response to hemorrhage in fetal animals. To determine whether PRL increases after hemorrhage in older animals, 11 immature female swine were prepared chronically under halothane and conditioned behaviorally to lie in a sling. They were bled 14 ml/kg over 5 min. PRL, ACTH, cortisol (F), lysine vasopressin (LVP), and pressure renin activity (PRA) were measured by radioimmunoassay. Epinephrine (EPI) and norepinephrine (NE) were separated by high-performance liquid chromatography. Arterial PRL increased at 0.75 and 1 h (P less than 0.01) and paralleled ACTH and F that peaked at 0.75 h (P less than 0.05 and P less than 0.01, respectively). All three hormones recovered significantly by 4 h. In contrast, PRA and LVP peaked transiently at 0.25 h after hemorrhage and recovered by 1.5 h (P less than 0.05, in each case). EPI and NE did not change significantly. In individual pigs, ACTH and F each showed correlations (Spearman) with PRL that were positive in 10 pigs and significant in six and five pigs, respectively. The pig with the smallest ACTH change (8.4 pg/ml peak) showed no increase in PRL. Peaks in PRL were simultaneous with (five pigs) or delayed by 15 min (four pigs) or 30 min (one pig) from peaks in ACTH. Significant correlations of PRL with PRA and with LVP occurred in only two pigs and in one pig, respectively. A common pathway may contribute to other independent mechanisms controlling the release of ACTH and PRL after hemorrhage.
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PMID:Response of prolactin to hemorrhage is similar to that of adrenocorticotropin in swine. 215 59

Serotonin has a facilitatory role in the role of prolactin and adrenocorticotropin (ACTH) secretion. The serotonin precursor 5-hydroxy-L-tryptophan (5-HTP) dose dependently (30-100 mg/kg i.p.) increased plasma prolactin and ACTH in the male rat. Prolactin and ACTH responses to 5-HTP (100 mg/kg) were attenuated by pretreatment with the non-selective 5-HT receptor antagonist, metergoline (0.5 mg/kg), and by the selective 5-HT2 receptor antagonists, ritanserin (0.4 mg/kg), ketanserin (2.5 mg/kg), ICI (5.0 mg/kg) and spiperone (1.0 mg/kg). The 5-HT1 receptor antagonists, propranolol (40 mg/kg) and pindolol (4.0 mg/kg), failed to antagonize the prolactin and ACTH responses to 5-HTP (100 mg/kg), as did the selective 5-HT3 receptor antagonist, BRL 43694 (1.0 mg/kg). The results suggest that the prolactin and ACTH responses to 5-HTP in the male rat are mediated by 5-HT2 receptors.
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PMID:Mediation of ACTH and prolactin responses to 5-HTP by 5-HT2 receptors. 216 47

To study the physiological roles of endogenous opioid peptides in drinking and feeding behaviors, the effects of water deprivation and fasting on plasma immunoreactive (IR) beta-endorphin (beta-end), IR-Antidiuretic hormone (ADH) and IR-Prolactin (Prl), pituitary IR-beta-end and IR-methionine-enkephalin (IR-Met-enk) and IR-ADH, and hypothalamic IR-beta-end and IR-Met-enk were observed in rats. The effects of water deprivation on hypothalamic dopaminergic system was also studied. In water deprived rats, plasma IR-beta-end and Prl were decreased significantly. In the neurointermediate lobe, IR-Met-enk, but not IR-beta-end, was decreased, although these peptides did not change in the anterior lobe and hypothalamus. Intraperitoneal injection of haloperidol reversed the decrease in plasma IR-beta-end in water deprived rats but did not change it in control rats. Subcutaneous injection of CB-154, on the other hand, decreased the plasma IR-beta-end in control rats but not in water deprived rats. The dopamine (DA) turnover rate in hypothalamus, in addition, was increased in water deprived rats as compared with controls. In fasted rats, IR-beta-end in plasma, but not in pituitary lobes and hypothalamus, was increased. The present results suggest that the increase of hypothalamic dopaminergic activity, in part, is related to the suppressed secretions of pituitary IR-beta-end and Prl in water deprivation, and plasma IR-beta-end play some roles in feeding behavior in rats.
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PMID:Influences of water deprivation and fasting on hypothalamic, pituitary and plasma opioid peptides and prolactin in rats. 294 40


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