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)

1. Preliminary, general chemical characteristics of substances in artificial sea water (ASW) washed through stimulated body wall (SBW) and in hemolymph taken from noxiously stimulated animals (SHL) were consistent with those of classical neurotransmitters, amino acids, and small- to medium-sized peptides. 2. 5-Hydroxytryptamine (5HT) and acetylcholine (ACh), unlike SBW and SHL, caused relaxation when perfused into isolated body wall. FMRFamide produced a biphasic response--brief contraction followed by prolonged relaxation. 3. Small cardioactive peptide (SCPB) caused body wall contractions similar to those produced by SBW and SHL, except that SCPB contractions displayed more desensitization and were completely blocked by 30 mM CoCl2. SCPB and SBW contractions were synergistic. 4. Dopamine caused persistent body wall contractions similar to those of SBW and SHL. Dopamine contractions were reduced but not blocked by 30 mM CoCl2. Unlike SBW activity, dopamine activity was reduced by alkalinization. 5. Glutamate and taurine produced strong but usually short-lasting body wall contractions. Adenosine, octopamine, arginine vasotocin, and cholecystokinin (CCK-8) caused weak or variable contractions. Met-enkephalin and somatostatin caused no obvious body wall responses. 6. When superfused over the fully sheathed abdominal ganglion, FMRFamide, met-enkephalin, glutamate, aspartate, and taurine reduced the magnitude of the gill-withdrawal reflex elicited by siphon nerve stimulation. 7. Taken together with earlier results, these data suggest a preliminary framework for trauma signal pathways. It is proposed that stress hormones (perhaps including FMRFamide, SCPs, 5HT, and dopamine) are released into hemolymph from neuroendocrine cells. Effective amounts of active intracellular solutes such as amino acids may also be released by extensive cellular rupture. Various humoral signals produce slow effects that contribute to hemostasis, balling up, increased cardiac output, and reflex suppression.
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PMID:Humoral factors released during trauma of Aplysia body wall. II. Effects of possible mediators. 276 Feb 88

Of three casein phosphatases isolated from the cytosol of human cord blood erythrocytes two were cobalt-dependent, E2 and E3. In the presence of CoCl2, E2 activity was the most prominent. In addition to casein, E2 dephosphorylated phosvitin and p-nitrophenyl phosphate (p-NPP) with pH optima at 6.8-7.2 for proteins and 9.0 for p-NPP. The native enzyme had a molecular weight of 104,000 daltons after AcA-44 Ultrogel filtration. According to SDS/PAGE it consisted of two subunits, 78,000 and 15,000 daltons. The 104,000-dalton form exhibited Michaelis-Menten kinetics and had the greatest affinity for casein between protein substrates tested. Ethanol denaturated the enzyme by 80%. Optimal activation of E2 phosphatase was achieved with 5 mmol/l CoCl2 which did not affect the catalytic properties of the enzyme but did affect the rate of 'E-S' complex formation. Inorganic pyrophosphate was not inhibitory for the 104,000-dalton enzyme. Judging by all these properties the natural substrate for E2 casein phosphatase could be P-pyruvate kinase.
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PMID:Cobalt-dependent protein phosphatases from human cord blood erythrocytes. II. Further characterization of E2 casein phosphatase. 283 85

The effect of histamine on the release of beta-endorphin-like immunoreactivity (beta-END LI) in rats was studied in vivo and in vitro experiments. Intravenous injection of 100 micrograms/100g BW of histamine resulted in a significant increase in the plasma beta-END-LI level 5, 15 minutes after the injection. Histamine at concentrations of 10(-12) to 10(-9)M also caused dose-dependent stimulation of release of beta-END-LI from the dispersed cells of the anterior pituitary of rats. On gel-chromatography, the beta-END-LI released by incubating the cells with 10(-9)M histamine consisted of two components, which eluted in the same positions as human beta-lipotropin and human endorphin, respectively. Addition of 2mM CoCl2 to the incubation medium inhibited histamine-induced beta-END LI release from the cells. Histamine H1 receptor antagonist (10(-6)M) inhibited histamine-induced beta-END-LI release from the cells. Histamine H2 receptor antagonist (10(-6)M), however, did not inhibit histamine-induced beta-END-LI release. These results indicate that histamine acts directly on the anterior pituitary cells to stimulate beta-END-LI release and that calcium ion is involved in the mechanism of this effect.
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PMID:[In vivo and in vitro effects of histamine on the release of beta-endorphin-like immunoreactivity]. 287 89

Anterior pituitary quarters were incubated in vitro and the release of beta-endorphin-like (beta-End-IR) and adrenocorticotropin-like immunoreactivity (ACTH-IR) was determined. The effect of phospholipase A2 as well as the effect of various compounds known to influence arachidonic acid metabolism under certain conditions were examined. Phospholipase A2 increased the release of beta-End-IR and ACTH-IR. This effect was reversible, concentration-dependent (1-400 ng/ml) and inhibited in calcium-free medium and in the presence of CoCl2 (5 mM) or phospholipase A2 inhibitors (p-bromophenacylbromide, 21 microM; mepacrine, 1 mM). The phospholipase A2-induced beta-End-IR release was accompanied by the release of prostaglandin E2. Inhibition of cyclooxygenase activity by indomethacin (14 or 140 microM) did not change beta-End-IR release induced by phospholipase A2 (5 ng/ml). The effects of blockers of lipoxygenase (nordihydroguaiaretic acid, NDGA; AA861) or lipoxygenase plus cyclooxygenase (BW755C; eicosatetraynoic acid, ETYA) on phospholipase A2-induced release of beta-End-IR were diverse. BW755C (up to 250 microM) and AA861 (up to 100 microM) produced no effect. However, NDGA or ETYA inhibited phospholipase A2-induced beta-End-IR release. NDGA (100 microM) produced a maximum inhibition by about 40% (p less than 0.05), whereas ETYA (100 microM) produced a maximum inhibition by about 85% (p less than 0.001). These data are consistent with the view that phospholipase A2 releases endogenous arachidonic acid which is transformed into products which stimulate ACTH and beta-endorphin release from the corticotrophs; the metabolizing enzyme (possibly a lipoxygenase or epoxygenase) is sensitive to NDGA and especially to ETYA.
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PMID:Effect of various blockers of arachidonic acid metabolism on release of beta-endorphin- and adrenocorticotropin-like immunoreactivity induced by phospholipase A2 from rat adenohypophysis in vitro. 301 92

Release of vasopressin (AVP) and oxytocin (OT) from rat median eminence and posterior pituitary tissue was studied in vitro by incubation in Krebs-56 mM KCl buffer. Both total tissue content and releasable pool of each hormone was measured in control rats, adrenalectomized rats and dexamethasone-treated rats. Adrenalectomy resulted in significantly increased release of AVP, but not OT, from median eminence tissue, whereas dexamethasone treatment failed to affect release of either hormone. Neither treatment had any effect on AVP or OT release from posterior pituitary tissue. Similarly, neither treatment caused any significant changes in total median eminence or posterior pituitary AVP and OT contents relative to controls, although dexamethasone-treated rats had a significantly lower posterior pituitary OT content than adrenalectomized rats. KCl-stimulated hormone release from median eminence tissue most likely represents an estimate of AVP and OT in zona externa terminals rather than in zona interna axons, because release was blocked by CoCl2 indicating calcium-dependent exocytosis. Immunohistochemical staining of median eminence tissue correlated well with the results of in vitro hormone release, in that increased AVP staining in the zona externa of adrenalectomized rats was also the only significant change noted using this methodology. Since increased levels of releasable AVP in the median eminence probably reflects similarly increased AVP levels in the hypothalamo-hypophyseal portal vessels of adrenalectomized rats, these results support a potential physiologic role for median eminence AVP, but not OT, in the chronic stimulation of adrenocorticotropin hormone secretion following adrenalectomy.
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PMID:In vitro release of vasopressin and oxytocin from rat median eminence tissue. 370 65

The effect of cholecystokinin octapeptide (CCK-8) on the release of beta-endorphin-like immunoreactivity (beta-EpLI) in rats was studied in vivo and in vitro. Intravenous injection of 5 micrograms/100 g body weight of CCK-8 resulted in significant increase in the plasma beta-EpLI level after 10 and 20 min. CCK-8 at concentrations of 10(-10) - 10(-6) M also caused dose-dependent stimulation of beta-EpLI release from dispersed cells of rat anterior pituitary. However, CCK-4 and desulfated CCK-8 had no effect. On gel chromatography, the beta-EpLI released by incubation of the cells with 10(-8) M CCK-8 separated into two components, eluted in the same positions as human beta-lipotropin and human beta-endorphin, respectively. CCK-8 did not stimulate beta-EpLI release in Ca++-free medium. A 23187 at concentrations of 10(-6) - 10(-3) M caused dose-dependent stimulation of beta-EpLI release from the cells. Addition of 2 X 10(-3) M CoCl2, 10(-3) M verapamil or 10(-7) M dexamethasone to the incubation medium inhibited CCK-8-induced beta-EpLI release from the cells. Dibutyryl cyclic GMP (3 X 10(-3) M) inhibited CCK-8-induced beta-EpLI release from the cells. Ouabain (10(-5) M) also stimulated beta-EpLI release but its effect was not additive with that of CCK-8. These results indicate that CCK-8 acts directly and specifically on anterior pituitary cells to stimulate beta-EpLI release and that calcium ion is involved in the mechanism of this effect.
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PMID:In vivo and in vitro effects of cholecystokinin octapeptide on the release of beta-endorphin-like immunoreactivity. 630 91

Two aminopeptidases which hydrolyze Metenkephalin at the Tyr-Gly bond have been solubilized from rat brain membranes and resolved by ion-exchange chromatography. These aminopeptidase are designated MI and MII based on the order in which they are eluted during ion-exchange chromatography. The two aminopeptidases can be distinguished kinetically; aminopeptidase MI hydrolyzes L-arginine beta-naphthylamide 17 times faster than L-alanine beta-naphythylamide, while only a 1.7-fold difference is exhibited by aminopeptidase MII. Aminopeptidase MII exhibits a higher affinity for amino acid beta-naphthylamides, Met-enkephalin, Leu-enkephalin, and the inhibitor puromycin as compared to aminopeptidase MI. Greater than 90% of aminopeptidase MII activity is lost upon dialysis against ethylene-diaminetetraacetate (EDTA) but can be reconstituted with CoCl2 and MnCl2. In contrast, aminopeptidase MI loses only 30% of its activity when dialyzed against EDTA. In addition to cleaving the Tyr-Gly bond of Met-enkephalin, aminopeptidase MII also cleaves the Tyr-Gly bond of alpha- and gamma-endorphin. Hydrolysis of Met-enkephalin by intact membranes derived from whole rat brain occurs primarily by cleavage at the Tyr-Gly bond, with this activity attributable to aminopeptidase MII.
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PMID:Solubilization and characterization of two rat brain membrane-bound aminopeptidases active on Met-enkephalin. 723 6