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)

Stimulation of beta adrenergic receptors on AtT-20 cells increases intracellular cyclic AMP levels and adrenocorticotropin hormone (ACTH) release. Pretreatment of these cells with catecholamines reduces the ability of (-)-isoproterenol to stimulate both cyclic AMP formation and ACTH secretion. This beta receptor desensitization is time- and dose-dependent and is reversible. Various beta adrenergic agonists can induce this desensitization with a rank order of potency of salmefamol greater than or equal to (-)-isoproterenol greater than or equal to epinephrine greater than or equal to norepinephrine greater than or equal to (+)-isoproterenol. (+/-)-Propranolol but not practolol can block the (-)-isoproterenol-induced beta receptor desensitization. Long-term treatment of AtT-20 cells with (-)-isoproterenol reduces the density of beta receptors but does not affect the affinity of these sites for [3H]dihydroalprenolol. In addition to desensitizing beta receptors, (-)-isoproterenol pretreatment enhances basal ACTH secretion. This effect was dose-dependent and blocked by (+/-)-propranolol. Forskolin-stimulated cyclic AMP formation and ACTH secretion was not altered by (-)-isoproterenol treatment indicating that the desensitization of beta receptors on AtT-20 cells is the result of receptor-adenylate cyclase uncoupling. No cross-desensitization of corticotropin releasing factor or vasoactive intestinal peptide receptors occurred as (-)-isoproterenol treatment did not alter the effect of these peptides on cyclic AMP synthesis or ACTH secretion.
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PMID:Desensitization of beta adrenergic receptors linked to adrenocorticotropin secretion. 613 52

Immunohistochemical investigations were carried out on 16 pheochromocytomas for a study of their immunoreactivity to methionine-enkephalin, vasoactive intestinal peptide, somatostatin, corticotropin, beta-endorphin, and calcitonin on serial semithin araldite sections. All antiserums except anti-beta-endorphin, selectively stained a variable number of distinct tumor cells. Methionine-enkephalin-immunoreactive cells were the most frequent. The neuropeptide content of pheochromocytomas appears highly diverse and unpredictable. These findings are supportive of the concept of multisecretory APUD cells of neural crest origin and rule out any of these neuropeptides as reliable immunohistochemical markers for tumor chromaffin cells.
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PMID:Immunohistochemical study of pheochromocytomas. An investigation of methionine-enkephalin, vasoactive intestinal peptide, somatostatin, corticotropin, beta-endorphin, and calcitonin in 16 tumors. 614 Aug 50

Somatostatin-14 (SRIF) inhibits both hormone- and forskolin-stimulated cyclic adenosine 3':5'-monophosphate (cyclic AMP) formation in tumor cells of the mouse anterior pituitary (AtT-20/D16-16). However, long-term pretreatment of cells with SRIF modifies the responsiveness of this system in two ways: The response of adenylate cyclase to stimulatory agents is enhanced, whereas the ability of SRIF to inhibit stimulated cyclic AMP formation is reduced. The supersensitive adenylate cyclase response and the SRIF desensitization were dependent on the concentration and duration of SRIF pretreatment. Enhancement of forskolin-stimulated cyclic AMP formation occurred within 4 hr, whereas that of corticotropin-releasing-factor-, (-)-isoproterenol-, and vasoactive intestinal peptide-induced cyclic AMP accumulation required 16 hr of pretreatment. The elevated responses to each of these stimulants were due to increases in their maximal ability to stimulate cyclic AMP formation. Cycloheximide treatment blocked the enhanced cyclic AMP response induced by SRIF pretreatment, suggesting a requirement for protein synthesis. In membrane preparations, SRIF pretreatment facilitated activation of adenylate cyclase by forskolin, sodium fluoride, and guanosine 5'-(beta,tau-imido)-triphosphate without affecting basal activity. These results suggest that desensitization of an inhibitory input to adenylate cyclase is accompanied by a supersensitivity of adenylate cyclase to stimulatory agents through a process requiring protein synthesis.
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PMID:Somatostatin pretreatment desensitizes somatostatin receptors linked to adenylate cyclase and facilitates the stimulation of cyclic adenosine 3':5'-monophosphate accumulation in anterior pituitary tumor cells. 614 35

Stress stimulates several adaptive hormonal responses. Prominent among these responses are the secretion of catecholamines from the adrenal medulla, corticosteroids from the adrenal cortex, and adrenocorticotropin from the anterior pituitary. A number of complex interactions are involved in the regulation of these hormones. Glucocorticoids regulate catecholamine biosynthesis in the adrenal medulla and catecholamines stimulate adrenocorticotropin release from the anterior pituitary. In addition, other hormones, including corticotropin-releasing factor, vasoactive intestinal peptide, and arginine vasopressin stimulate while the corticosteroids and somatostatin inhibit adrenocorticotropin secretion. Together these agents appear to determine the complex physiologic responses to a variety of stressors.
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PMID:Stress hormones: their interaction and regulation. 614 3

A series of 25 apudomas of the gastrointestinal tract (22 cases), bronchus (2 cases), and thymus (1 case) were subjected to staining with silver impregnation (Masson-Fontana and Grimelius) techniques and with the commercial immunoperoxidase kits for the peptide hormones adrenocorticotropin, calcitonin, gastrin, glucagon, growth hormone, human chorionic gonadotropin (hCG), insulin, somatostatin, and vasoactive intestinal peptide. Of the tumors studied, 16 were regarded as malignant, and 5 of the patients showed clinical symptoms due to inappropriate hormone secretion. A total of 16 tumors contained cells positive for 1 or more (6 were multihormonal) of the hormones studied. One bronchial carcinoid stained for hCG, which has not been previously reported. In addition, one of the rectal carcinoids contained somatostatin-positive cells, only once described previously. The thymic tumor proved frankly malignant, most probably identical to the oat-cell carcinoma recently described. The findings also substantiate the recent suggestion that gastrointestinal carcinoids cannot be adequately classified on the basis of silver stains only and strongly advocate the use of the immunoperoxidase kits in routine assessments of all the endocrinologically active tumors, whatever their localization might be.
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PMID:Stainability of the peptide hormones in gastrointestinal apudomas as demonstrated by immunoperoxidase kits. 614 78

The purpose of the present study was to compare the potency, effectiveness and duration of action of synthetic bPTH-(1-34) with those of other known hypotensive peptides in the anesthetized dog. Of sixteen peptides tested in the present study only 8 were demonstrated to possess hypotensive activity. While bPTh-(1-34) was one of the least potent of the hypotensive peptides, it was equal to or greater than the other peptides in terms of effectiveness and duration of action. Of all the peptides studied, substance P and eledosin were the most potent in terms of their hypotensive action. It is suggested that perhaps substance P and eledoisin might act at a different site or through different mechanisms than do vasoactive intestinal peptide (V.I.P.), corticotropin inhibiting peptide (C.I.P.), neurotensin, xenopsin, bradykinin and bPTH-(1-34).
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PMID:Pharmacological comparison of bPTH-(1-34) and other hypotensive peptides in the dog. 617 Sep 59

Calmodulin exhibits high-affinity, calcium-dependent binding of 1 mol/mol of the vasoactive intestinal peptide (VIP), secretin, and either the 42- or 43-residue gastric inhibitory peptide (GIP) with dissociation constants of 0.05-0.14 microM. The affinity of VIP for calmodulin approaches its affinity for the cell-surface VIP receptors. These peptides compete with both smooth muscle myosin light chain kinase and glucagon in calmodulin binding. Calculation of amino acid frequencies for eight calmodulin binding peptides (VIP, GIP, secretin, ACTH, beta-endorphin, substance P, glucagon, and dynorphin [Malencik, D. A., & Anderson, S. R. (1982) Biochemistry 21, 3480]) shows a below-average incidence of glutamyl residues, above-average incidence of glutaminyl residues, and average incidence of both aspartyl and asparaginyl residues. Predictions of structure from sequence suggest that the bound peptides contain strongly basic turns and coils in close association with regions having above-average beta-sheet potential. The temperature dependence of glucagon binding by calmodulin shows that the association is enthalpy driven.
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PMID:Binding of hormones and neuropeptides by calmodulin. 618 15

The effects of vasoactive intestinal peptide (VIP) and several other peptides have been examined on cyclic AMP accumulation in intact pieces and isolated horizontal cells of the teleost (carp) retina. VIP was the most effective peptide examined, inducing a dose-related response, and an approximately fivefold increase in cyclic AMP production when used at a concentration of 10 microM. Porcine histidine isoleucine-containing peptide and secretin, peptides structurally related to VIP, also stimulated cyclic AMP accumulation, but at concentrations of 10 microM induced responses which were only approximately 40% and 10%, respectively, of the response observed with 10 microM VIP. In contrast, several other peptides, including glucagon, neurotensin, somatostatin, luteinizing hormone-releasing hormone, alpha-melanocyte-stimulating hormone, cholecystokinin octapeptide26-33, gastrin-releasing peptide, thyrotropin-releasing hormone, and VIP10-28 were totally inactive. The response to 10 microM VIP was not antagonized by several dopamine antagonists, indicating the presence of a population of specific VIP receptors coupled to adenylate cyclase, distinct from the population of dopamine receptors coupled to adenylate cyclase also known to be present in this tissue. Finally, experiments involving the use of fractions of isolated horizontal cells indicate that these neurons possess a population of VIP receptors coupled to cyclic AMP production which would appear to share a common pool of adenylate cyclase with a population of similarly coupled dopamine receptors.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of vasoactive intestinal peptide and other peptides on cyclic AMP accumulation in intact pieces and isolated horizontal cells of the teleost retina. 619 61

Surfactants, a group of nonspecific membrane perturbating substances, can cause nerve damage. Various concentrations of the cationic surfactants benzalkonium chloride (BAC) and benzethonium chloride, the anionic surfactants sodium ricinoleate, dioctyl sodium sulfosuccinate and sodium lauryl sulfate and the nonionic surfactant Triton X-100 were applied to the serosal surface of the rat jejunum every 5 min for 0.5 hr and then rinsed off with saline. Thirty days after surfactant application, the treated and an untreated segment of jejunum were removed and examined histologically. All surfactants which were tested significantly reduced the number of ganglion cells in the myenteric plexus. In addition, sodium ricinoleate significantly reduced the number of ganglion cells in the submucosal plexus. Higher concentrations of the cationic agents BAC and benzethonium chloride caused a generalized tissue damage including disruption of the smooth muscle, lymphocytic infiltration, intestinal perforation and death. Using BAC as a prototype surfactant, peptidergic neuron distribution and gut electrical activity were examined. BAC treatment markedly reduced the immunoreactivity of somatostatin, substance P, met-enkephalin and vasoactive intestinal peptide in the myenteric plexus. In addition, the electric properties of the smooth muscle were altered. BAC treatment resulted in an erratic, markedly distorted basic electric rhythm and an alteration in spike potential generation. These studies demonstrate that surfactants in appropriate concentrations selectively ablate the myenteric neurons and alter peptidergic neuron distribution and gut electrical parameters in the rat jejunum.
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PMID:Surfactants selectively ablate enteric neurons of the rat jejunum. 619 30

The effects of beta-endorphin and vasoactive intestinal peptide (VIP) on the body shaking response to ice water immersion were observed in anesthetized rats. Intraventricular injection of beta-endorphin markedly inhibited body shaking, but gamma- and alpha-endorphin and methionine-enkephalin showed only slight or little effect. VIP also suppressed the body shaking. The inhibitory effect of beta-endorphin and VIP was blocked by naloxone. When small doses of beta-endorphin and VIP which could not affect the shaking behavior by themselves were administered simultaneously, significant suppression occurred, indicating potentiation of the effect of beta-endorphin by VIP.
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PMID:Suppressive effect of beta-endorphin on body shaking response to ice water immersion and synergistic action of vasoactive intestinal peptide on beta-endorphin in anesthetized rats. 619 39


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