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)

In order to examine the capacity of pharmacologically useful opiates to stimulate human mast cell secretion, subjects were skin tested with morphine, codeine, or meperidine hydrochloride. All three agents acted equipotently in eliciting positive immediate skin reactions from all subjects tested. Each agent demonstrated 10 mm of net whealing at 5 to 10 micrograms base (16.7 to 40.4 nmol) injected intradermally. The ability to elicit immediate skin test reactions with endogenous opioid peptides was examined with the use of dynorphin, [D-Ala, 2-D-Leu5] enkephalin, beta-endorphin, and morphiceptin . All four compounds induced wheal-and-flare reactions with the order of potency: dynorphin, greater than beta-endorphin, and greater than [D-Ala, 2-D-Leu5] enkephalin approximately equal to morphiceptin at dose ranges of 0.3 to 8.45 nmol. The inhibition of reactivity by hydroxyzine and the demonstration of mast cell degranulation by electron microscopy suggest that the immediate skin responses to opioid stimulation occur as a consequence of mast cell degranulation. Experiments with the opioid receptor antagonist, naloxone, suggest that both opioid and nonopioid receptors may be involved. These results imply that endogenous opioid peptides possibly may play a role in mast cell function and/or degradulation .
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PMID:Induction of human cutaneous mast cell degranulation by opiates and endogenous opioid peptides: evidence for opiate and nonopiate receptor participation. 632 90

It is shown that met-enkephalin and morphine injected intraperitoneally to rats in a dose of 0.15 mg/kg do not significantly affect the elaboration of conditioned reaction to place in a T-maze with food reinforcement. D-Ala-met-enkephalin amid in the same dose increases the number of unaccomplished reactions on the 2-nd day of learning without eliciting significant changes of other parameters. Leu-enkephalin and D-Ala-D-Leu-enkephalin (intraperitoneally, 0.15 mg/kg) increase the number of unaccomplished reactions and the time of maze-run when injected before the learning seances. D-Ala-D-enkephalin increases the time of run at its injection "immediately after" the learning seances as well. In this case the Leu-enkephalin is not effective. The obtained data show that enkephalin effects in this experimental test to a certain extent correlate with peptides' ability of binding tightly with delta-opiate brain receptors. Different effects of met- and leu-enkephalins confirm the hypothesis on diversity of peptides' functions in the central nervous system.
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PMID:[Effect of enkephalins on training the white rat in a T-maze]. 635 58

It is shown that leu-enkephalin, injected intraperitoneally in doses of 0.15 and 1.0 mg/kg lowers general motor activity of rats in "Animex" apparatus in 10-30 min after the injection. D-substituted analogue of leu-enkephalin D-Ala-D-Leu-enkephalin (0.15 mg/kg) lowers the motor activity already in first 5 min after injection. Met-enkephalin, DALA and morphine in a dose of 0.15 mg/kg do not change the general motor activity of rats in "Animex". Concentration raise of opiate ligands to 1.0 mg/kg does not lead to the development of significant effect in the case of met-enkephalin, but elicits an increase of motor activity under the action of morphine to 25-30 min after injection. During the study of animals' behaviour in "the open field" the leu-enkephalin and D-Ala-D-Leu-enkephalin lower the level of certain emotional reactions in rats, while met-enkephalin and DALA are not effective.
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PMID:[Effect of enkephalins on the motor activity and behavior of rats in "open field" conditions]. 666 33

The effects of some previously unexplored beta-lipotropin derivatives (fragments of beta-MSH 4-7 and 5-8 corresponding to fragments of beta-lipotropin 40-43, 41-44; an enkephalin analog--an enkephalin-like tetrapeptide Tyr-D-Ala-Gly-Phen-NH2) on drinking and food behavior of rats were studied and compared. beta-MSH 5-8 was found to possess a remarkable dipsogenic action but to produce no effect on food intake in rats. At the same time a structurally related analog beta-MSH 4-7 and enkephalin-like tetrapeptide did not alter drinking behavior of animals, exerting, however, a substantial satiating action on hungry rats and initiating food behaviour in fed animals. The effects of the peptides on drinking and food behavior appeared long-term, persisting for 14-16 days and even up to 4-4.5 months upon administration of the enkephalin-like tetrapeptide. The data obtained suggest that the structural similarity of peptides does not always determine the common characteristics of their physiological effects which depend to a considerable degree on the initial food motivation.
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PMID:[Effect of beta-lipoprotein derivatives on the drinking and feeding behavior of rats]. 670 13

1 Dermorphin and Hyp6-dermorphin are the first representatives of a new class of potent opioid peptides occurring in amphibian skin. They present the unique feature of having a D-Ala residue incorporated in the peptide molecule. 2 Dermorphin displayed a potent depressive action on electrically stimulated contractions of the guinea-pig ileum and mouse vas deferens preparations. Dermorphin was respectively 57,294, 18 and 39 times more potent than Met-enkephalin, Leu-enkephalin, beta-endorphin, and morphine on the guinea-pig ileum opiate receptors. On the vas deferens receptors, dermorphin was about as potent as the enkephalins and 40 times more potent than morphine. Naloxone was a powerful antagonist to dermorphin in both preparations. 3 Dermorphin produced potent and long-lasting analgesia in mice by intravenous injection, and in rats by intracerebroventricular injection, the ED50 being here of the order of 13-23 pmol/rat. Morphine was 752 and 2170 times less potent, depending on the analgesia test used. At high intracerebroventricular doses analgesia was accompanied by catalepsy. 4 Intracerebroventricular infusion of dermorphin induced development of tolerance and precipitation of withdrawal symptoms upon administration of naloxone. Both tolerance and physical dependence was consistently less marked with dermorphin than with morphine. 5 The minimum sequence requirement for full dermorphin activity was represented by the N-terminal tetrapeptide. The presence of the D-Ala2-residue was of crucial importance.
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PMID:Pharmacological data on dermorphins, a new class of potent opioid peptides from amphibian skin. 719 58

In chicks (Gallus domesticus) the effects of beta-endorphin and D-Ala-2-methionine-enkephalinamide given into the third cerebral ventricle on behaviour, electrocortical activity and body temperature were studied. Dose-dependent behavioural stuporous state, decrease in painful stimuli and hypothermic effects were observed after both peptides. Electrocortical high-amplitude slow frequency waves occurred during behavioural sedation and stupor. Spectrum power analysis has allowed to quantify the ECoG activity and has revealed an increase in total voltage output with a predominant increase within the lower spectrum frequencies. The hypothermic effects were significantly more marked when chicks were kept at ambient temperature below their thermoneutral range. Behavioural, electrocortical and body temperature effects were rapidly reversed by naloxone showing that these effects are mediated through an activation of specific opioid receptors.
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PMID:Effects of intraventricular beta-endorphin and D-ALA2-methionine-enkephalinamide on behaviour, spectrum power of electrocortical activity and body temperature in chicks. 739 25

Receptors mediating opiate-induced inhibition of potassium-stimulated release of [3H]norepinephrine (NE) from slices of rat cortex incubated in vitro have been characterized by comparison of the pA2 values of the competitive antagonists, naloxone, D-Pen-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), nor-binaltorphimine, naltrindole and bremazocine against the agonists, Tyr-D-Ala-MePhe-Gly-ol (DAMGO), Tyr-D-Arg-Phe-Sar (TAPS), [D-Ser2, Leu5]enkephalyl-Thr (DSLET), beta-endorphin [beta-END(1-31)] and ethylketocyclazocine (EKC). There were significant differences among agonists in their sensitivities to each antagonist. The delta receptor selective agonist, DPDPE, and the kappa 1-agonist, U69593, did not inhibit NE release, indicating that delta and kappa 1 receptors are not involved. DAMGO, TAPS and DSLET generally behaved as mu agonists, although TAPS and DSLET were less sensitive to antagonism by CTOP than by DAMGO. TAPS and DSLET showed similar sensitivities to all antagonists, suggesting that they acted through similar receptors, possibly of the mu 1 type. beta-END(1-31) and EKC differed from DAMGO and from each other in their sensitivities to most antagonists. Shifts in agonist concentration-response curves induced by prior treatment of the rats with the noncompetitive antagonists, beta-funaltrexamine and naloxonazine, also suggested that EKC and beta-END(1-31) acted through mechanisms differing from those used by DAMGO, TAPS and DSLET. It is possible that EKC and beta-END(1-31) acted via kappa 2 and/or epsilon receptors. These results suggest that there is heterogeneity in the opioid receptors regulating NE release in rat cortex.
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PMID:Inhibition of norepinephrine release from rat cortex slices by opioids: differences among agonists in sensitivities to antagonists suggest receptor heterogeneity. 826 76

The effects of substance P (SP) and the naturally occurring met-enkephalin and the synthetic mu-specific opioid agonist, DAGO (Tyr-D-Ala-Gly-N-Methy-Phe-Gly-ol) and the delta-specific opioid agonist DADL (Tyr-D-Ala-Gly-Phe-D-Leu) on basal ventilation were investigated in halothane-anaesthetized rats. Local injections of SP (0.75-1.5 nmol) in the ventrolateral medulla oblongata (VLM), e.g. nucleus paragigantocellularis, and nucleus reticularis lateralis increased ventilation because of an elevation of tidal volume. Met-enkephalin induced a short-lasting ventilatory depression mainly because of a depression of tidal volume. Activation of delta- and mu-opioid receptors in the VLM by local application of DADL and DAGO, respectively, induced ventilatory depression, which was later in onset and more long-lasting. Local administration of met-enkephalin into the VLM also produced a long-lasting inhibition of the SP-induced ventilatory excitation. A similar blockade of the SP-induced excitatory ventilatory response could be elicited by DADL but not by DAGO. This antagonistic effect was attenuated by local application of the delta-opioid receptor antagonist ICI 154. 129. We conclude that the naturally occurring met-enkephalin as well as synthetic mu- and delta-specific enkephalin analogues (DAGO and DADL, respectively) in VLM depress basal ventilation by an effect on inspiratory drive. There is a functional antagonism between activation of delta-opioid receptors and SP receptors into the VLM in respect to respiratory regulation.
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PMID:Substance P-induced respiratory excitation is blunted by delta-receptor specific opioids in the rat medulla oblongata. 880 Mar 56

Results of energy calculations for alpha-MSH (alpha-melanocyte stimulating hormone, Ac-Ser1-Tyr2-Ser3-Met4-Glu5-His6-Phe7-Arg8-Trp9- Gly10-Lys11-Pro12-Val13-NH2) and [D-Phe7] alpha-MSH were used for design of cyclic peptides with the general aim to stabilize different conformational isomers of the parent compound. The minimal structural modifications of the conformationally flexible Gly10 residue, as substitutions for L-Ala, D-Ala, or Aib (replacing of hydrogen atoms by methyl groups), were applied to obtain octa- and heptapeptide analogues of alpha-MSH(4-11) and alpha-MSH(5-11), which were cyclized by lactam bridges between the side chains in positions 5 and 11. Some of these analogues, namely those with substitutions of the Gly10 residue with L-Ala or Aib, showed biological activity potencies on frog skin comparable to the potency of the parent tridecapeptide hormone. Additional energy calculations for designed cyclic analogues were used for further refinement of the model for the biologically active conformations of the His-Phe-Arg-Trp "message" sequence within the sequences of alpha-MSH and [D-Phe7]alpha-MSH. In such conformations the aromatic moieties of the side chains of the His6, L/D-Phe7, and Trp9 residues form a continuous hydrophobic "surface," presumably interacting with a complementary receptor site. This feature is characteristic for low-energy conformers of active cyclic analogues, but it is absent in the case of inactive analogues. This particular spatial arrangement of functional groups involved in the message sequence is very close for alpha-MSH and [D-Phe7]alpha-MSH, as well as for biologically active cyclic analogues despite differences of dihedral angle values for corresponding low-energy conformations.
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PMID:Studies of conformational isomerism in alpha-melanocyte stimulating hormone by design of cyclic analogues. 969 65

1. The actions of opioid receptor agonists on the calcium channel currents (IBa) of acutely dissociated periaqueductal grey (PAG) neurons from C57B16/J mice and mutant mice lacking the first exon of the mu-opioid receptor (MOR-1) were examined using whole cell patch clamp techniques. These effects were compared with the GABA(B)-receptor agonist baclofen. 2. The endogenous opioid agonist methionine-enkephalin (met-enkephalin, pEC50 6.8, maximum inhibition 40%), the putative endogenous mu-opioid agonist endomorphin-1 (pEC50 6.2, maximum inhibition 35%) and the mu-opioid selective agonist DAMGO (Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol enkephalin, pEC50 6.9, maximum inhibition 40%) inhibited IBa in 70% of mouse PAG neurons. The inhibition of IBa by each agonist was completely prevented by the mu-receptor antagonist CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2). The delta-opioid receptor agonists DPDPE ([D-Pen2,5]enkephalin, 1 microM) and deltorphin II (1 microM), and the kappa-opioid receptor agonist U-69593 (1-10 microM), did not affect IBa in any cell tested. 3. The GABA(B) agonist baclofen inhibited IBa in all neurons (pEC50 5.9, maximum inhibition 42%). 4. In neurons from the MOR-1 deficient mice, the mu-opioid agonists met-enkephalin, DAMGO and endomorphin-1 did not inhibit IBa, whilst baclofen inhibited IBa in a manner indistinguishable from wild type mice. 5. A maximally effective concentration of endomorphin-1 (30 microM) partially (19%), but significantly (P<0.005), occluded the inhibition of IBa normally elicited by a maximally effective concentration of met-enkephalin (10 microM). 6. This study indicates that mu-opioid receptors, but not delta- or kappa-opioid receptors, modulate somatic calcium channel currents in mouse PAG neurons. The putative endogenous mu-agonist, endomorphin-1, was a partial agonist in mouse PAG neurons.
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PMID:Mu-opioid receptor modulation of calcium channel current in periaqueductal grey neurons from C57B16/J mice and mutant mice lacking MOR-1. 1032 86


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