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)

Rats were subjected to nigro-striatal hemitransection and then intracerebroventricularly infused with the potent and long-acting alpha-MSH analogue, (Nle4, D-Phe7)alpha-MSH, at two different doses (15 or 30 ng/h/rat), or with saline (0.6 microliter/h/rat), continuously for 14 days starting on day 2 after lesion. (Nle4, D-Phe7)alpha-MSH dose-dependently improved the sensorimotor deficit (postural asymmetry, impaired limb reflexes and coordinated limb use, signs of cortical and pyramidal lesion), reduced turning behaviour induced by apomorphine, and increased spontaneous motility in the open field. 3H-Spiperone binding showed that (Nle4, D-Phe7)alpha-MSH treatment caused a down regulation of the striatal DA receptors in the lesioned side, contrary to the supersensitivity developed by the corresponding receptors of saline treated rats. These results indicate that melanopeptides improve the functional recovery of nigro-striatally hemitransected rats, by an action at CNS level.
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PMID:Improved recovery of nigro-striatally hemitransected rats induced by (Nle4, D-Phe7)alpha-MSH: a central effect. 283 66

Developmental and long-term behavioral effects of perinatal injection of beta-endorphin (BE), CRF and Tyr-Pro-Leu-Gly-NH2 (Tyr-MIF-1) in male rats were investigated along with the possibility that opiate receptors may be altered by the injection of BE during this critical time. Daily injections of peptide were given to pregnant females (100 micrograms/rat) in the week before birth or to the offspring (50 micrograms/rat) of untreated mothers during the first week of life. Prenatal BE and CRF reduced body weight on day 1, in contrast to Tyr-MIF-1 which produced a significant increase over controls by day 7 as well as a slight but significant acceleration of eye opening. Among the postnatal treatments, CRF-treated animals showed the most dramatic changes. These included decreased body weight, accelerated eye opening, and, in adulthood, increased open field rearing behavior and a tendency for a monotonic body temperature response to low doses of morphine, in contrast to the biphasic response shown by controls. BE, when given to pregnant mothers, increased the number (Bmax) of [3H]naloxone-labeled (mu) receptors in whole brains of offspring assayed on day 14, but it did not significantly alter [3H]D-Ala-D-Leu-enkephalin-labeled (delta) receptors. In contrast, a significant decrease in both mu and delta receptors was observed on day 14 in rats given BE postnatally. These differences in receptors were no longer apparent in adulthood, and no significant differences in tail-flick response were detectable at this time. Nevertheless, some of the effects of these three peptides endured well beyond their presence, and for BE included changes in the number of opiate receptors.
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PMID:Developmental, behavioral, and opiate receptor changes after prenatal or postnatal beta-endorphin, CRF, or Tyr-MIF-1. 286 78

The effect of beta-endorphin, met-enkephalin and leu-enkephalin on cold-stimulated TSH and prolactin secretion after infusion of the drugs into the 3rd ventricle or into the posterior hypothalamus (PH) was investigated in male rats. beta-endorphin (0.25 microgram/rat, but not 0.05, 0.5 and 1 microgram/rat) increased and met-enkephalin (20 and 100 micrograms/rat) decreased TSH secretion when infused into the 3rd ventricle. After bilateral infusion into the PH, beta-endorphin (0.25 microgram/side, but not 0.05 and 1 microgram/side) increased TSH secretion, but met-enkephalin (1 and 10 micrograms/side) induced no changes. beta-endorphin (0.05-1 microgram/rat) and met-enkephalin (100 micrograms/rat) both increased prolactin secretion when infused into the 3rd ventricle, but only a high dose of beta-endorphin (1 microgram/side) was effective after infusion into the PH. Leu-enkephalin had no effect on TSH or prolactin secretion at the hypothalamic level. These results favour the hypothesis that mu-receptors mediate the inhibitory effect and other types (possible epsilon-receptors) of opiate receptors mediate the stimulatory effect of opioid peptides on TSH secretion at periventricular sites. However, only stimulatory mu-receptors affect prolactin secretion at these sites. After infusion into the PH, the effect of a high dose of beta-endorphin on prolactin secretion may also be mediated through periventricular sites, but its effect on TSH secretion is evidently mediated through opiate receptors in the PH.
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PMID:Opioid peptides in the regulation of TSH and prolactin secretion in the rat. 295 56

The effects of morphine, adrenocorticotropic hormone (ACTH) and formalin on plasma corticosterone levels were investigated in the nucleus reticularis gigantocellularis (NRGC)-lesioned rats. ACTH (1.0 U/kg) or formalin (6.4%, 0.2 ml/rat) elevated plasma corticosterone in both sham-lesioned and NRGC-lesioned rats at the same degree, while morphine (10 mg/kg) also elevated plasma corticosterone in sham-lesioned rats, the elevation of which was significantly reduced by NRGC-lesioning. These findings suggest that the NRGC is involved in the corticosterone-increasing effect of morphine, but not involved in the effect of ACTH or formalin.
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PMID:Participation of the nucleus reticularis gigantocellularis in the morphine-induced elevation of plasma corticosterone in rats. 299 29

The effect of administration of a high dose of glucocorticoid (triamcinolone) on serum lipids and lipoproteins was studied in rats. Changes in serum lipids, especially cholesterol, were most marked when 5 mg/kg body weight of triamcinolone was injected daily for 5 days. Serum lipoproteins were separated by ultracentrifugation followed by gel-filtration chromatography. Cholesterol distribution between apolipoprotein B-containing lipoproteins (very-low-density and low-density lipoproteins), high-density lipoprotein1 (HDL1), and HDL2 was determined after administration of triamcinolone with or without additional treatment with adrenocorticotropin (ACTH; Cortrosyn, 6 IU/rat). When triamcinolone was administered, cholesterol concentrations in HDL1 and HDL2 were elevated in a dose-dependent manner, but there was no significant change in apolipoprotein B-containing lipoprotein cholesterol levels. When ACTH was administered in combination with triamcinolone, the concentrations of all serum lipids except triacylglycerol were significantly lowered compared with rats treated with triamcinolone alone. HDL1-cholesterol concentration in serum was significantly (P less than 0.001) lowered from 69 +/- 13 mg/dl (mean +/- S.D.) in triamcinolone-treated rats to 36 +/- 4 mg/dl by the administration of ACTH plus triamcinolone. The additional administration of ACTH in triamcinolone-treated rats caused a slight, but significant, decrease in cholesterol concentration in apolipoprotein B-containing lipoproteins; however, HDL2-cholesterol level was not significantly affected, although there was a tendency for it to be lowered.
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PMID:Glucocorticoid-induced elevation of serum high-density lipoprotein-cholesterol and its reversal by adrenocorticotropin in the rat. 302 35

In its initial encounter with growth hormone (GH) in vitro, epididymal fat excised from GH-deficient rats responds with an insulin-like increase in glucose metabolism. Tissues freshly excised from normal rats are refractory to the insulin-like effects of GH, but become sensitive immediately after surgical stress. Reversal of refractoriness is prevented by administration of the opioid antagonist, naloxone, just prior to stress, suggesting a possible role of beta-endorphin or related peptides. These experiments were undertaken to determine the source of these peptides which might equally well be released from the pituitary, adrenal medullae, or nerve endings in response to stress. Since adrenalectomy, like stress, also results in increased secretion of adrenocorticotropic hormone (ACTH) and related peptides, we studied the effects of GH on glucose oxidation in adipose tissue obtained from adrenalectomized rats and found a significant insulin-like response to GH in tissues studied 4 days after adrenalectomy. This effect was not due to GH deficiency, since plasma concentrations were only slightly reduced by adrenalectomy. Administration of naloxone (250 micrograms/rat), 30 or 60 min before sacrifice, or dexamethasone (100 micrograms/injection), 60 and 120 min before sacrifice, prevented a response to GH without affecting circulating levels of GH. The effects of adrenalectomy could not be reproduced by preincubation of adipose tissue from normal nonstressed rats with ACTH and beta-endorphin, but were duplicated by preincubation of adipose tissue for 15 min in medium in which pituitary glands had previously incubated in the presence of corticotropin-releasing hormone (0.1 microM) and arginine vasopressin (0.2 microM). Addition of naloxone (250 micrograms/ml) blocked this effect.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pituitary secretions related to adrenocorticotropic hormone induce sensitivity of adipose tissue to the insulin-like actions of growth hormone. 303 37

ACTH (1 unit per 1 rat) induced a 6-fold increase of the corticosterone synthesis in adrenals and a 2-fold increase of its secretion into the blood. Met-enkephalin (15 micrograms/kg) also increase the corticosterone secretion, the level of the hormone in the blood, however, becoming even lower. Combined action of these two substances involved a greater increase of the hormone concentration in the gland than in case of each of them separately. The hormone content in the blood remained low in this case, too. In perfusion of an isolated adrenal gland with met-enkephalin (15 micrograms/ml), no increase in the corticosterone concentration was observed either in the perfusate samples. The data obtained suggest that met-enkephalin activates synthesis of corticosteroids, on the one hand, and inhibits their secretion into the blood, on the other hand, whereas ACTH activates both these processes.
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PMID:[Direct effect of met-enkephalin on the synthesis and secretion of corticosterone by the adrenal glands of the rat]. 304 Apr 80

IPL nude females present an absence of lactation with hypoprolactinemia. While males present a slight but significant decrease in serum testosterone and gonadotropins, females show normal values of estradiol, progesterone, LH and FSH during all estrus cycle stages. In this work, we observed that the postovariectomy rise of LH and FSH was significantly lower in the IPL nude females. We studied also the effect of acute (1 injection of 25 micrograms/rat E2Bz) or long-term (E2Bz capsule for 8 days) estradiol benzoate (E2Bz) treatment, with or without progesterone injection (5 mg/rat) in ovariectomized (OVX) IPL and normal females. The sensitivity of gonadotropins to E2 negative feedback is decreased in the IPL nude rats, result in agreement with previous reports and which could be linked to both hypoprolactinemia and decreased beta-endorphin observed in the IPL nude rat. The responsiveness of LH to LHRH was also tested in OVX and OVX + E2Bz or OVX + E2B + P treated. In OVX females responsiveness of LH to LHRH was similar in IPL nude to that of normal females. However, LH responsiveness in acute and long-term steroid-treated OVX IPL nude was significantly depressed. Since the mechanism whereby PRL interacts with steroids to modify gonadotropin secretion is still unexplained, IPL nude rat could be a good model to study it.
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PMID:Steroid regulation of gonadotropins in genetically hypoprolactinemic females (IPL nude rats). 308 74

The possible involvement of endogenous opioid peptides in the development of the facilitatory effect of adrenaline on memory has been investigated. For this purpose post-training administration of adrenaline and/or naloxone was carried out in rats tested in an inhibitory avoidance paradigm and subjected or not to pre-training (extensive familiarization with the training situation prior to the acquisition trial). Adrenaline injected subcutaneously in a dose of 500 micrograms/kg facilitated retention performance in rats both subjected or not to pre-training. Naloxone administered SC (400 micrograms/rat) did not influence retention behaviour in rats subjected or not to pre-training, nor did ICV (0.80 ng/rat) administration. Interestingly, the opiate antagonist when injected SC (400 micrograms/rat) prevented the facilitatory effect exerted by adrenaline in pretrained as well as in not pre-trained rats. However, ICV administration of naloxone (0.80 microgram/rat) dit not influence the behavioral effects exerted by the bioamine. These data suggested a role of endogenous opioid peptides on the facilitatory effect of adrenaline on memory, possibly independent of novelty factors and thus of the brain beta-endorphin system. In addition, our results point to the periphery as the most likely site for such interaction.
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PMID:Naloxone prevents the facilitatory effect upon retention induced by adrenaline administration in rats. 312 49

The synthetic opioid met-enkephalin analog [D-Ala2, MePhe4, Met(0)5ol] enkephalin (DAMME) and the opiate morphine injected intraperitoneally to rats at doses of 0.5-2 and 5-20 mg/kg, respectively, showed a protective effect on gastric damage induced by oral administration of necrotizing agents (0.6 N HCl or 0.2 N NaOH solutions, 1 ml/rat). The protection was prevented by naltrexone (10 mg/kg s.c.), an opioid antagonist with long-lasting activity. Histological sections of mucosal samples from animals pretreated with morphine (10 mg/kg i.p.) and DAMME (1 mg/kg i.p.) showed less alteration of the columnar epithelium, with a normal glandular structure, than untreated rats. A mediation of prostaglandins is suggested, since indomethacin (10 mg/kg s.c.) significantly reduced the protective effects of opioids.
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PMID:Protection by opioids against gastric lesions caused by necrotizing agents. 335 41


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