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)

Systematic analysis of the hydrolysis of benzyloxycarbonyl (Cbz)-dipeptides by cathepsin A [EC 3.4.12.1] purified from rat liver lysosomes showed that multiple forms of cathepsin A preferentially cleave peptide bonds with leucine, methionine, and phenylalanine. Cbz-Met-Met, -Met-Phe, -Phe-Met, and -Phe-Ala were hydrolyzed 6 to 8 times faster than the standard substrates, Cbz-Glu-Phe and Cbz-Glu-Tyr. The pH optima of the hydrolyses were 4.6 to 5.8. Hydrolysis of peptide bonds with glycine, isoleucine, and proline was very slow, but the rate depended on the nature of the adjacent amino acids. Proteins such as albumin, cytochrome c, gamma-globulin, hemoglobin, histone, myoglobin, and myosin were scarecely degraded. Peptide hormones, such as glucagon and adrenocorticotropic hormone (ACTH) were hydrolyzed markedly with optimum pH's of 4.5 and 4.6, respectively. Angiotensin I, II, bradykinin, Lys- and Met-Lysbradykinin (kallidin and Met-kallidin), and substance P were also hydrolyzed at appreciable rates. pH optima for these peptide hormones were 5.2 to 5.6. On the other hand, insulin and its A chain, luteinizing hormone-releasing hormone (LH-RH), oxytocin and vasopressin were cleaved slowly. In the hydrolyses of glucagon and other peptides, multiple forms of rat liver lysosomal cathepsin A again showed a carboxypeptidase nature, cleaving peptide bonds sequentially from the carboxyl terminal. Almost all of the amino acids were cleaved on prolonged incubation. Vaso-activites of angiotensin II and bradykinin were rapidly lost on hydrolysis by cathepsin A. Lysosomal cathepsin C [dipeptidylaminopeptidase I, EC 3.4.14.1] also activated angiotensin II, but did not inactive bradykinin. Cathepsin A, therefore, can be regarded as one of the lysosomal angiotensinases and kinases. No distinct differences were observed between the multiple forms of cathepsin A in these hydrolyses and inactivations of peptides.
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PMID:Studies on cathepsins of rat liver lysosomes. III. Hydrolysis of peptides, and inactivation of angiotensin and bradykinin by cathepsin A. 1 61

Biologically active peptides and neurotransmitter substances were added to anterior pituitary cell cultures to examine the presence of corticotropin releasing factor (CRF)-like activity. Hypothalamic extract (HE) induced significant dose-related increase of ACTH, and the lowest effective dose was 0.01 HE/ml. Other tested substances including luteinizing hormone-releasing hormone, thyrotropin releasing hormone, melanocyte stimulating hormone release inhibiting factor, somatostatin, substance P, neurotensin, beta-endorphin. leu-enkephalin, met-enkephalin, bradykinin, norepinephrine, dopamine, serotonin, acetylcholine, histamine, gamma-amino butyric acid or gamma-hydroxy butyric acid showed no CRF-like activity. Relatively high doses of lysine vasopressin, arginine vasopressin and angiotensin II increased the release of ACTH in pituitary cell cultures, but the maximal ACTH response was markedly less than with HE. These results indicate that cultured anterior pituitary cells are sensitive and fairly specific in detecting CRF(s) comparing with other detecting procedures.
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PMID:Specificity of cultured anterior pituitary cells in detecting corticotropin releasing factor(s): the effect of biologically active peptides and neurotransmitter substances on ACTH release in pituitary cell cultures. 3 34

Structure-activity studies have been performed on a series of naturally occurring and 'tailor-made' polypeptides, by measurement of ability to induce selective histamine release from normal rat peritoneal mast cells in vitro. Compounds investigated include corticotropin and melittin derivatives, mast-cell-degranulating peptide from bee venom, polymyxin B, bradykinin and various synthetic poly(amino acids) and short-chain peptides. It was confirmed that a cluster of four basic residues (lysine or arginine) was optimal for histamine release by corticotropin and melittin polypeptides, provided that the C-terminal carboxyl group was substituted (by, for instance, amidation). In contrast, the presence of a free C-terminal carboxyl group or nearby dicarboxylic acid residues led to a considerable diminution in histamine-releasing activity. Likewise, polypeptides comprised essentially of acidic amino acids were inactive. On the basis of these observations it has been possible to predict that synthetic peptides comprising a particular sequence within the Fc region of human immunoglobulin E, the immunoglobulin class particularly involved in mediation of allergic reactions of the immediate type, would possess potent histamine-releasing activity when similarly made to react with normal rat mast cells. The further study of such a structure should throw new light on the molecular basis of allergen-antibody triggering of mast cells.
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PMID:Further studies on the structural requirements for polypeptide-mediated histamine release from rat mast cells. 9 86

The antinociceptive and hypothermic effects of intracisternal administration of 11 endogenous neuropeptides and morphine were evaluated in mice. Of the substances tested, only neurotensin (NT) and beta-endorphin exerted significant antinociceptive and hypothermic effects; NT was the most potent in inducing hypothermia whereas beta-endorphin was the most potent antinociceptive agent via this route of administration. Both NT, and beta-endorphin were, on a molar basis, considerably more potent antinociceptive agents than morphine, [Met]enkephalin, or [Leu]enkephalin. NT-induced analgesia and hypothermia both were significantly dose-dependent. Substance P was found to produce significant hyperalgesia and hyperthermia. Bombesin produced a significant hypothermic effect, whereas somatostatin and luteinizing hormone-releasing hormone (luliberin) produced hyperthermia. None of the other peptides studies [bradykinin, thyrotropin-releasing factor (thyroliberin), melanocyte-stimulating hormone release-inhibiting factor (melanostatin), somatostatin, [Met]enkephalin, and [Leu]enkephalin] produced any significant alterations in colonic temperature or response to a noxious stimulus with the doses tested. These data demonstrate that NT and beta-endorphin, two endogenous brain peptides, are potent in inducing hypothermia and in producing an antinociceptive state.
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PMID:Alterations in nociception and body temperature after intracisternal administration of neurotensin, beta-endorphin, other endogenous peptides, and morphine. 29 52

The effects of alpha-MSH and several other vasoactive substances on the mesenteric vascular bed were studied in the anesthetized cat under conditions of controlled blood flow. Intra-arterial injections of alpha-MSH in doses of 10, 30, and 100 mug resulted in significant dose-related decreases in mesenteric arterial perfusion pressure but little or no effect on systemic arterial pressure. The vasodilator response to alpha-MSH was breif in duration and resistance to flow was decreased 10, 18, and 26 percent at 10, 30, and 100 mug. These significant changes after alpha-MSH were of a much smaller magnitude than were observed after prostaglandins E1 and E2, isoproterenol, bradykinin or glyceryl trinitrate and differed completely from the increased resistance after angiotensin II and norepinephrine.
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PMID:Comparison of alpha-MSH and several vasoactive substances on vascular resistance in the feline mesenteric vascular bed. 82 86

The adrenal cortex contains a kallikrein-like enzyme that may lead to bradykinin (BK) formation. This study was designed to determine whether BK acts on adrenocortical cells to stimulate steroid secretion. BK, Lys-BK, a specific BK 2 (B2) receptor agonist, and desArg9-BK, a specific BK 1 (B1) receptor agonist, all stimulated aldosterone secretion from cultured bovine adrenal zona glomerulosa cells. BK and Lys-BK were equipotent (EC50 = 2 x 10(-9) M), whereas desArg9-BK was 1000-fold less potent. The maximal effects of BK and BK analogs were comparable to the maximal effects of adrenocorticotropin or angiotensin II. A B2, but not a B1, receptor antagonist inhibited BK-stimulated aldosterone release. Verapamil and N,N-diethylamino-octyl-3,4,5-trimethoxybenzoate, which reduce intracellular calcium concentrations, reduced BK-stimulated aldosterone secretion. Although BK stimulated both prostacyclin and aldosterone production, indomethacin abolished prostacyclin production without affecting aldosterone secretion. In cultured adrenal fasciculata cells, high concentrations of BK stimulated cortisol release, but B1 or B2 receptor agonists were not effective. BK-stimulated cortisol secretion was reduced by N,N-diethylamino-octyl-3,4,5-trimethoxybenzoate but not by indomethacin. In summary, BK stimulates aldosterone release from cultured adrenal glomerulosa cells via high affinity B2 receptors. The effect is calcium-dependent and independent of prostaglandins. BK also increases cortisol release; however, this stimulation requires high concentrations of BK and may be mediated by an unknown receptor or by a receptor-independent mechanism.
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PMID:Bradykinin stimulates aldosterone release from cultured bovine adrenocortical cells through bradykinin B2 receptors. 131 40

We evaluated whether the brain kallikrein-kinin system plays a role in the regulation of adrenocorticotropin (ACTH) release in rats. Intracerebroventricular (icv) injection of bradykinin (0.24 nmol) increased plasma immunoreactive ACTH (irACTH) levels (from 93 +/- 4 to 200 +/- 12 pg/ml, P less than 0.01). This effect was prevented by icv kinin antagonist at 15.4 nmol/h (from 98 +/- 5 to 108 +/- 6 pg/ml; not significant). The antagonist did not alter the increase in plasma irACTH levels induced by icv corticotropin-releasing factor (CRF), arginine vasopressin, or prostaglandin E2. Melittin (7 nmol/h icv) increased plasma irACTH from 95 +/- 4 to 268 +/- 7 pg/ml (P less than 0.01). This effect was prevented by icv kinin antagonist (15.4 nmol/h), kallikrein antibodies (13 pmol/h), or indomethacin (0.28 mmol/h). ACTH response to melittin was not altered by antagonists of CRF or vasopressin. Intra-arterial injection of insulin (0.3 IU/kg body wt) reduced plasma glucose levels to a similar extent in rats given icv kinin antagonist or vehicle; the ACTH response to insulin-induced hypoglycemia was slightly less in rats given kinin antagonist than in those given vehicle (55 +/- 5 vs. 86 +/- 4 pg/ml, P less than 0.05). The brain kallikrein-kinin system may play a role in the regulation of ACTH secretion in stimulated conditions.
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PMID:Role of brain kallikrein-kinin system in regulation of adrenocorticotropin release. 131 88

Peptides have recently been found to function as neuromodulators or neuromediators within nociceptive pathways at central and peripheral sites. More complex and varied in their chemistry compared to "classical" low molecular weight monoamine neurotransmitters, peptides may nonetheless co-exist with these within a single neuron. The biological activity of a peptide results from an "address" segment that permits receptor binding and a "message" segment that initiates reactions within the cell. Opioid peptides (endorphins) are derived from three precursors and act by altering ionic fluxes of potassium or calcium across cell membranes. Nonopioid peptides active in nociception include calcitonin and its gene-related peptide C.G.R.P., bradykinin, substance P, somatostatin, cholecystokinin, and corticotropin-releasing hormone, among others. Ongoing investigations show significant responses of several peptide systems in experimental models relevant to vascular pain. Although the creation of novel peptide analogues has therapeutic promise, their present clinical use must be cautious in light of reports of neurotoxicity after intraspinal application of some of these compounds in animal models.
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PMID:Neuropeptides and pain. 170 17

To verify whether plasma beta-endorphin and bradykinin affects the pathophysiology of myocardial ischemia and the perception of cardiac pain, 35 patients with coronary artery disease were subjected to treadmill testing and 48-hour Holter ECG monitoring to measure their pain thresholds. Patients were divided into two groups during exercise testing: group 1 (N = 19) who had ST segment depression, and group 2 (N = 16), who had chest pain. Both groups were then compared with 12 age-matched control subjects. Pain thresholds were measured after Holter ECG monitoring, and blood samples were drawn before and immediately after exercise. No statistical differences were noted between groups 1 and 2 with regard to the severity of myocardial ischemia as assessed by ST segment depression or exercise tolerance time. The frequency of the episodes of silent myocardial ischemia in group 1 was found to be significantly (p less than 0.05) higher than that in group 2. The duration of the episodes of silent myocardial ischemia in group 1 was 41.9 minutes (range 3 to 343 minutes), which was significantly (p less than 0.05) longer than that in group 2 (11.5 minutes; range 0 to 74). The pain threshold in group 1 was a statistically (p less than 0.05) higher value than that in group 2. Although the resting plasma beta-endorphin level in group 1 was not statistically significantly different from values in either group 2 or the control group, during exercise the plasma beta-endorphin levels in both group 1 and the control group were significantly (p less than 0.05) elevated in comparison with their resting levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differences in plasma beta-endorphin and bradykinin levels between patients with painless or with painful myocardial ischemia. 173 63

The ability of a number of drugs and neuropeptides to stimulate phosphoinositide metabolism in cultured bovine adrenal medullary cells has been assessed. Low concentrations (10 nM) of angiotensin II, bradykinin, histamine, arginine-vasopressin, and bombesin, and high (10 microM) concentrations of oxytocin, prostaglandins E1, and E2, beta-endorphin, and neurotensin stimulated significant accumulation of [3H]inositol phosphates in adrenal medullary cells preloaded with [3H)]inositol. Bradykinin stimulated a significant response at concentration as low as 10pM, with an EC50 of approximately 0.5 nM. The response was markedly inhibited by the bradykinin B2 antagonist [Thi5,8,D-Phe7] bradykinin but not the B1 antagonist [Des-Arg9,Leu8] bradykinin. Higher concentrations of bombesin and neurotensin were required to elicit a response (10 nM and 10 microM respectively). The bombesin response was sensitive to inhibition by the bombesin antagonist [D-Arg1,D-Pro2,D-Trp7,9Leu11]-substance P. In contrast, the neurotensin response was not reduced by the NT1 antagonist [D-Trp11]-neurotensin. These results indicate there are a number of agents that can stimulate phosphatidylinositide hydrolysis in the adrenal medullary cells by acting on different classes of receptors. Such a range of diverse agonists that stimulate inositol phosphate formation will facilitate further analysis of the phosphatidylinositide breakdown in chromaffin cell function.
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PMID:Receptor stimulated formation of inositol phosphates in cultures of bovine adrenal medullary cells: the effects of bradykinin, bombesin and neurotensin. 217 99


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