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 the present study, the role of the endogenous opioid peptide systems in the regulation of blood pressure during standardized, stepwise hemorrhagic hypotension was investigated in anesthetized rats. Central as well as peripheral administration of naloxone resulted in an increase in the bleeding volumes required to reduce blood pressure. Bleeding volumes also increased after the peripheral injection of naloxone methobromide, an analog of naloxone that does not readily cross the blood-brain barrier. Following central administration of antisera against beta- and alpha-endorphin and dynorphin A(1-13), the amount of blood that had to be withdrawn to induce hypotension was elevated. In rats treated with an antiserum against [Met5] enkephalin or gamma-endorphin, bleeding volumes did not differ from those of rats treated with control serum. These data indicate that activation of central and possibly also of peripheral opiate receptors plays a role in the control of blood pressure during blood loss. Dynorphin A(1-13), beta- and alpha-endorphin, or closely related peptides might be the endogenous ligands for the receptors that are blocked by naloxone.
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PMID:Endogenous opioid peptides and blood pressure regulation during controlled, stepwise hemorrhagic hypotension. 172 53

Investigations have shown the presence of a cardiodepressant factor in the fluid incubating the posterior pituitary lobe "in situ", which decreased contraction frequency of the isolated heart auricle (Acta Physiol. Pol., 1984, 35: 460-468). The influence on the spontaneous contraction frequency of the isolated heart auricle of the following synthetic neuropeptides was determined: substance P, leu-enkephalin, met-enkephalin, angiotensin II, arg-vasopressin, oxytocin, delta sleep-inducing peptide and atrial natriuretic factor. It was found that the investigated neuropeptides had no effect on the contraction frequency of the isolated auricle of the heart right atrium of two-day-old rat in a concentration from 2.1 x 10(-7) to 1 x 10(-3) mol/l in the bathing medium and it was concluded that their biological properties differ from the cardiodepressant factor.
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PMID:The lack of influence of some neuropeptides present in the posterior pituitary lobe on the frequency of spontaneous contraction of the isolated heart auricle. 172 1

Morphine, leu-enkephalinamide, met-enkephalin, alpha-neoendorphin and its Arg8 1-8 fragment increase contractile vacuole output in the freshwater Amoeba proteus at 18 microM. Significant effects of leu-enkephalin and naloxone are obtained at 180 microM. All compounds have reached their maximal activity at 720 microM. Alpha-neoendorphin and leu-enkephalin are inactive in the presence of isotonic, non-penetration sucrose, hence these compounds increase plasma membrane permeability to water. Results from molecular modeling show a clear correlation of activity with amphiphilicity, charge distribution and general flexibility of molecules. We conclude that, like previously-studied vasopressin analogues and non-hormonal amphiphilic peptides, active opioids embed themselves into the Amoeba plasma membrane, disrupting the lipid bilayer and increasing its permeability. In our Amoeba system, naloxone, a general morphine-like inhibitor, blocks active opioids as well as a vasopressin analogue. Naloxone, being less active than other tested amphiphiles, acts as a membrane stabilizer, protecting the lipid bilayer against the disruption action of more active compounds.
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PMID:Direct membrane effects of morphine and endorphins on Amoeba proteus. 173 Nov 68

Primary paraganglioma arises infrequently in the urinary bladder. We present the clinicopathologic, immunohistochemical, ultrastructural, and DNA flow cytometric findings in three cases (one man and two women). Ages at diagnosis were 19, 35, and 45 years. One female presented with paroxysmal headaches and hypertension that followed urination; the remaining two patients presented with hematuria. Immunohistochemical studies revealed positive reactivity for chromogranin (three patients), met-enkephalin (three), leu-enkephalin (three), vasoactive intestinal polypeptide (two), serotonin (one), and S-100 protein (one; sustentacular cells only). Neurosecretory granules were identified in all cases; in the patient with hypertension, the granules were small with eccentric cores similar to those of adrenal pheochromocytomas. A nondiploid DNA flow cytometric pattern was present in all three patients, an aneuploid pattern was present in two, and a tetraploid pattern was present in one. After diagnosis, one patient was alive without progression at 7 years, one died of an uncertain cause at 5 years, and one suffered multiple recurrences over a 24-year period before developing metastatic disease. While the presence of aneuploidy has been shown to be a predictor of malignant behavior in adrenal pheochromocytomas, our study illustrates that DNA ploidy cannot be used as a diagnostic criterion for malignancy in urinary bladder paraganglioma.
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PMID:Paraganglioma of the urinary bladder: immunohistochemical, ultrastructural, and DNA flow cytometric studies. 174 2

The results of bicycle ergometry and pharmacological tests with isoproterenol and dipyridamol, 24-hour monitoring and blood levels of endogeneous opioids were studied in 99 females with chest pain who had undergone angiography. Coronary microcirculation was examined in 29 patients by introducing albumin microspheres into the left ventricle. The angiography revealed coronary atherosclerosis in 30 patients, whereas its signs were not found in 8 females with documented coronary heart disease (CHD). The predictive value of positive exercise tests in females with angina pectoris was higher for the diagnosis of CHD, including its types without coronary atherosclerosis. In patients with cardialgias, the predictive values of exercise tests were equally low for the diagnosis of coronary atherosclerosis, vasospastic and microvascular CHD types. The patients with cardialgias caused by autonomic dyshormonal myocardiodystrophy showed low blood beta-endorphin and leu-enkephalin levels.
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PMID:[Diagnostic usefulness of ECG changes in response to exercise in women with various forms of ischemic heart disease]. 175 7

This review summarizes the revolutionary impact of brain peptides on our understanding of the nervous system and then discusses the localization, distribution, synthesis, receptor sites, and possible function of 32 brain peptides. The peptides are discussed in three subgroups: I) the opioid peptides, which include beta-endorphin, the enkephalins, and dynorphin; II) the pituitary releasing hormones, most of which are wide-spread in the brain and include corticotropin-releasing hormone, luteinizing hormone-releasing hormone, somatostatin, and thyrotropin-releasing hormone; and III) a selection of 12 other peptides potentially important for neurological function, including vasopressin, oxytocin, substance P, cholecystokinin, bombesin, neurotensin, renin, angiotensin, vasoactive intestinal polypeptide, neuropeptide Y, calcitonin gene-related peptide, and calcitonin. Within each individual peptide section, the possible physiological roles in anterior pituitary hormone release, blood-flow regulation, feeding behavior, temperature regulation, nociception, memory and learning, and movement are reviewed. Further, where noted, the peptide findings in Huntington's, Alzheimer's, Parkinson's and psychiatric diseases are emphasized.
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PMID:Neuropeptides. 187 Jul 24

By means of RIA, the contents of Leu-enkephalin, Met-enkephalin, and Beta-endorphin in CSF of 32 epileptic patients and 24 controls were determined. It was found that the mean Leu-enkephalin content in CSF of the epileptic patient group was significantly higher than that of the control group (P less than 0.01), whereas the mean contents of Met-enkephalin and Beta-endorphin in CSF showed no significant change as compared with those of the control group. The increase of Leu-enkephalin was not related to such factors as type of seizure, age of onset, length of time after the last seizure, taking of antiepileptic drugs, and abnormality in cranial CT manifestation. This suggested that endogenous opioid peptides might take part in the neurochemical mechanism of human epilepsy, and leu-enkephalin could play an important role in the development of epileptic episodes.
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PMID:[Opioid peptides in cerebrospinal fluids of epileptic patients]. 190 3

In a placebo-controlled, randomized, crossover, double-blind study of 17 normal volunteers, we examined the effects of captopril on the concentration of opioid peptides during bicycle exercise and on quality of life after a 2-week treatment period. Two exercise tests (progressive exercise and constant work rate exercise) were performed. Maximum oxygen uptake and blood lactate concentrations were measured in progressive exercise tests. The exercise intensities corresponding to a 1/2 lactate threshold, a lactate threshold, and a 4 mmol/L lactate concentration were determined. Constant work rate exercise at selected work loads for 20 minutes was carried out to measure the concentrations of opioid peptides and other hormones. Quality of life was assessed after the 2-week treatment period. Captopril treatment had no effect on the exercise response of blood pressure, heart rate, maximum VO2, and maximum work loads. The plasma concentrations of lactate, epinephrine, norepinephrine, and aldosterone increased during exercise and captopril did not change them. Beta-endorphin levels and plasma renin activity also increased during exercise, and the increases were greater with captopril treatment. Met-enkephalin and leu-enkephalin concentrations did not increase during exercise. According to responses in the quality of life questionnaires, administration of captopril improved the physiologic state more than the placebo did. These findings suggest that captopril may act on the central nervous system involving an increase in the beta-endorphin level.
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PMID:Effects of captopril on opioid peptides during exercise and quality of life in normal subjects. 195 Oct 4

1. A sucrose-gap technique was used to investigate the neuromodulatory actions of enkephalins on non-adrenergic, non-cholinergic inhibitory junction potentials (IJPs) in the circular muscle of the human large intestine. 2. The native enkephalins, [Leu5]enkephalin (LENK) and [Met5]enkephalin (MENK) caused a concentration-dependent reduction in amplitude of IJPs without a significant effect on the smooth muscle membrane. 3. The actions of LENK and MENK were mimicked by the delta-selective opioid receptor agonists [D-Pen2, D-Pen5]enkephalin (DPDPE) and [D-Ala2, D-Leu5]enkephalin (DADLE). 4. The actions of LENK, MENK and DPDPE were antagonized to similar extents by the delta-selective opioid receptor antagonist ICI 174,864. 5. The mu-selective opioid receptor agonist [D-Ala2, Me Phe, Gly-ol5]enkephalin was approximately 100-fold less potent than any of the native or synthetic enkephalins at reducing the amplitude of the IJP. Dynorphin A and beta-endorphin both had very weak activity. 6. Responses to all of the agonists were inhibited by naloxone. The degree of antagonism of DPDPE or DADLE by naloxone (1 microM) was the same as that of LENK or MENK. 7. Neither MENK nor LENK affected hyperpolarization of the smooth muscle membrane induced by ATP or 5-hydroxytryptamine. Vasoactive intestinal polypeptide (1 pM-1 microM) did not produce any observable responses and this lack of reactivity was not affected by the enkephalins. 8. It is concluded that in the circular muscle of the human colon, LENK and MENK can act on prejunctional delta-opioid receptors to produce inhibition of non-adrenergic, non-cholinergic inhibitory neuromuscular transmission. Possible physiological significance of this prejunctional receptor is discussed.
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PMID:Enkephalins modulate inhibitory neuromuscular transmission in circular muscle of human colon via delta-opioid receptors. 196 52

It was previously shown in this laboratory that high affinity binding of [125I]ACTH-(1-24) to membranes from rat brain was inhibited by vasoactive intestinal polypeptide (VIP), GH-releasing factor (GRF), and dynorphin (DYN), but not by other peptides tested. We now show that these peptides compete for [125I]VIP binding in brain and for [125I]ACTH-(1-24) binding in adrenal cortex and promote steroidogenesis. The high affinity sites for [125I]ACTH-(1-24) in the rat brain and bovine adrenal had Kd values of 0.51 +/- 0.41 and 3.9 +/- 1.3 nM, respectively; and the Ki values for VIP were 5.4 +/- 4.2 and 1.4 +/- 0.51 nM, respectively. In rat brain and bovine adrenal the high affinity site for [125I]VIP had Kd values of 2.9 +/- 1.7 and 0.5 +/- 0.8 nM, respectively, and Ki values for ACTH of 23.6 +/- 14.0 and 22.2 +/- 33.0 nM, respectively. In brain, DYN and GRF inhibited binding of [125I]VIP with Ki values of 49 and 30 nM, respectively. Cortisol secretion from isolated bovine adrenal cortical cells was significantly stimulated by 10(-10) M ACTH, VIP, DYN, or GRF, and a maximal response occurred for each at 10(-8) M. However, maximal cortisol production in response to VIP, DYN, or GRF was only about half that by ACTH-(1-24). The combination of ACTH-(1-24) and VIP, each at 10(-10) M, was additive in stimulating cortisol production, whereas each at 10(-8) M caused no greater response than ACTH alone. There was an additive steroidogenic effect of VIP plus ACTH-(1-10), but not VIP plus ACTH-(11-24). Specific binding of [125I]ACTH-(11-24) in adrenal membranes was inhibited by unlabeled ACTH-(11-24), ACTH-(1-24), VIP, GRF, and DYN, but not by ACTH-(1-10), peptide T, TRH, alpha MSH, or beta-endorphin; there was no specific binding of [125I]ACTH-(1-10). Functional studies and binding data, in conjunction with the existence of homologous amino acid sequences, indicate that VIP, GRF, and DYN interact at a subpopulation of ACTH receptors that recognizes a moiety within the 11-24 sequence of the ACTH molecule.
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PMID:Adrenocorticotropin, vasoactive intestinal polypeptide, growth hormone-releasing factor, and dynorphin compete for common receptors in brain and adrenal. 196 78


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