Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Data are presented, demonstrating the action of a number of oligopeptides on biological motivations of hunger, fear, self-stimulation and on alcohol addiction. In the structure of animals feeding motivation, such oligopeptides take part as beta-lipotropin and its fragments, ACTH, pentagastrin, delta-sleep inducing peptide (DSIP), substance P; in organization of defensive motivation--angiotensin II (AII), DSIP, substance P, bradykinin, beta-endorphin etc.; in organization of self-stimulation--AII, DSIP, bradykinin, ACTH, beta-endorphin etc. It is established that most of the above oligopeptides, injected to the brain lateral ventriculi, inhibit biological motivations, and only some of them have an activating action. On the basis of experiments, a hypothesis is formulated that oligopeptides act as a feedback between the genome of brain neurones and pacemaker cells of motivation centres of the hypothalamus area. Some oligopeptides elaborated by neuronal genomes under the action of dominating motivation, activate--and the other--suppress the activity of motivation hypothalamus centres.
 ...
PMID:[Oligopeptides in the development of biological motivations]. 357 22

A possible relationship between met-enkephalin (ME)-like peptides and bradykinin (BK) in the rat incisor pulp was examined in in vitro experiments using whole pulp. ME-like peptide content in the pulp was increased by BK at a concentration of 1 microM, but not in higher concentrations, while the release of ME-like peptides from the pulp into the incubation medium was increased dose-dependently by BK. These effects of BK were inhibited by Des-Arg9-[Leu8]-BK, a potent BK-antagonist, suggesting that the effects of BK were mediated through a specific BK-receptor in the pulp. On the other hand, high K+ did not induce any increased release of ME-like peptides from the pulp and the BK effects were influenced neither in Ca++-free medium nor in the presence of ouabain. These results suggested that ME-like peptide releasing effect of BK was not due to depolarization of the cell membrane and was not active. In addition, kyotorphin, and enkephalin-releaser, could not only elicit a release of ME-like peptides from the pulp, but also a marked increase of the peptide content in the pulp. However, a combination of BK and kyotorphin attenuated the effect of BK or kyotorphin each other. These results suggested that there might be two kinds of mechanisms of ME-like peptide production in the pulp and those mechanisms might interfere mutually.
 ...
PMID:In vitro production and release of opioid peptides in the tooth pulp induced by bradykinin. 373 92

The report of 'kallikrein-like' activity in the rat neuro-intermediate lobe (N-IL) and its possible involvement in pro-opiomelanocortin processing led us to explore the expression of the kallikrein gene(s) in the pituitary. Using 32P-labelled rat pancreatic kallikrein cDNA, we have shown positive hybridization for rat anterior pituitary poly(A)+ RNA, of identical size on Northern blots (approximately 1.0 kb) to rat kidney poly(A)+ RNA run in parallel. Prior adrenalectomy or ovariectomy decreased the level of kallikrein mRNA seen in the anterior pituitary; total RNA from rat N-IL showed no significant hybridization. On hybridization histochemistry the anterior pituitary was strongly positive, and the neural and intermediate lobes negative. The previously reported kallikrein-like activity in the N-IL is therefore probably due to a non-kallikrein kininogenase; in the anterior pituitary, kallikrein may have a physiological role in limited precursor proteolysis, but lack kininogen activity.
 ...
PMID:Kallikrein gene expression in the rat anterior pituitary. 384 24

A soluble metalloendopeptidase identified in rat brain, preferentially cleaves bonds in peptides having hydrophobic amino acid residues in the P1, P2, and P3' positions. (The nomenclature of T. Schechter and A. Berger is used to describe the interaction between enzyme and substrate. The amino acid residues in the substrate are designated as P1, P2, P3 etc. in the N-terminal direction and P1', P2', P3' etc. in the C-terminal direction from the bond undergoing cleavage. The corresponding subsites in the enzyme are identified by the letter S.) The degradation of a series of biologically active peptides and their affinity toward the enzyme was studied. Dynorphin-(1-8), alpha-neo-endorphin, and beta-neo-endorphin are rapidly hydrolyzed to form leu-enkephalin, whereas bovine adrenal medulla dodecapeptide is hydrolyzed to form met-enkephalin. The enzyme, however, does not cleave a larger precursor molecule of metenkephalin, such as bovine adrenal medulla docosapeptide. Several other bioactive peptides are also cleaved at sites consistent with our previously reported specificity studies. Met- and leu-enkephalin are resistant to hydrolysis. The binding affinity [as expressed by inhibitory constant (Ki) or Michaelis-Menten constant (Km) values] of several bioactive peptides such as dynorphin-(1-8), beta-neo-endorphin, neurotensin, angiotensin I, and bradykinin was found to be in the micromolar range. These peptides were also rapidly hydrolyzed by the enzyme, showing, as a result, high specificity constants (kcat/Km values). The highest enzyme activity was found in brain, testis, and in the anterior and posterior lobes of the pituitary, while the activity in such tissues as spleen, liver, kidney, lung, adrenals, and thyroid amounted to only 10-20% of that found in brain. This distribution of enzyme activity, together with its preference for oligopeptides as substrates, its ability to generate leu- and met-enkephalin from several larger peptide precursors, and its affinity toward several other bioactive peptides, suggests that the enzyme functions in the metabolism of neuropeptides.
 ...
PMID:Soluble metalloendopeptidase from rat brain: action on enkephalin-containing peptides and other bioactive peptides. 388 8

Two cell culture systems were used for studies of neural functions in vitro. A neuronal hybrid cell line (neuroblastoma x glioma hybrid cells) and primary glial-rich cultures of newborn murine brain. The level of cyclic AMP in both systems is regulated by two groups of hormones, those that stimulate and those that inhibit formation of cyclic AMP. Among the inhibitory hormones active on the hybrid cells are opioids. Therefore the cells are being used in the elucidation of action of opioids. The list of stimulating and inhibitory hormones regulating the primary glial-rich cultures includes several peptide hormones such as the gastrointestinal peptides secretin and vasoactive intestinal peptide, the calcaemic hormones parathyrin and calcitonin, adrenocorticotropin and melanotropins, and somatostatin. Noradrenaline (via alpha- and beta-adrenergic receptors) and adenosine (via A1 and A2 receptors) inhibit and stimulate cyclic AMP synthesis in the primary glial-rich cultures. Bradykinin slowly hyperpolarizes the hybrid cells and elicits formation of cyclic GMP. Both responses desensitize rapidly. Substance P increases the permeability of hybrid cells for Na+, as measured by using 14C-guanidinium as substitute for Na+. Hybrid cells actively accumulate taurine, an amino acid that appears to fulfill important functions in the nervous system. The transport of taurine across the plasma membrane is highly specific for and strictly dependent on Na+. The pumped station hypothesis of taurine action in the nervous system views taurine gradient plus taurine carrier as a transport system for the elimination of sodium from neurons during phases of high neuronal activity.
 ...
PMID:Cell culture as models for studying neural functions. 608 74

Nanomolar concentrations of neurotensin caused a dose-dependent contraction of the longitudinal muscle layer of the guinea-pig ileum. The contractile activity of neurotensin was partially blocked by tetrodotoxin or atropine, indicating that a component of the neurotensin-mediated contraction is indirect in nature and likely involves the release of endogenous acetylcholine from nervous terminals in the myenteric plexus. Dynorphin and related peptide fragments also blocked in part the neurotensin contraction; the potency of this opioid peptide was about the same as that of atropine. Other peptides and alkaloids tested for ability to block the neurotensin contractures included the enkephalins, beta-endorphin, normorphine and the ketocyclazocines; all these opioids inhibited in a dose-dependent fashion the neuronal component of the excitatory effect of neurotensin. The potency of these compounds to reduce the contractions of neurotensin showed good correlation with the potency of these agents to depress by 50% the electrically evoked neuromuscular twitches in the same tissue (r = 0.99); in these tests dynorphin was found to be the most potent of the endogenous opioid-like peptides. The dynorphin blockade was selective to the excitatory effect of neurotensin because the opioid peptide did not antagonize the contractile action of acetylcholine, histamine, substance P, angiotensin II, bradykinin, Ba++ or K+ ions. In addition, somatostatin, vasointestinal peptide, gastrin or adenosine did not modify the potency of neurotensin whereas thyrotropin releasing hormone and epinephrine caused a modest doubling of the neurotensin EC50. The inhibitory action of dynorphin was reduced in the presence of naloxone, suggesting that the interaction involved opiate receptors. Morphine tolerance was not extended to the inhibitory action of dynorphin as evidenced by the finding that the potency of dynorphin-(1-13) to block the neurotensin responses was increased after chronic morphine exposure. In contrast, the potency of dynorphin-(1-13) was significantly reduced in tissues rendered tolerant to the action of ketocyclazocine or ethylketocyclazocine, suggesting that the action of dynorphin could be partially mediated via occupation of K-opiate receptors. Thus, a cholinergic-neuronal component activated by neurotensin on the myenteric plexus appears to be under the inhibitory influence of opiate receptors, suggesting that dynorphin may play a role in the modulation of cholinergic synapses on the enteric nervous system.
 ...
PMID:Dynorphin inhibition of the neurotensin contractile activity on the myenteric plexus. 614 Dec 81

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).
 ...
PMID:Pharmacological comparison of bPTH-(1-34) and other hypotensive peptides in the dog. 617 Sep 59

The effects of intracerebroventricular administration of several peptides on discrete-trial, conditioned avoidance responding were assessed in the rat. Three peptides (neurotensin, bombesin and beta-endorphin) produced a neuroleptic-like effect (i.e. a decrease in avoidance responding with no effect on escape responding). A low dose (0.6 nmol) of each peptide elicited a significant effect. Neurotensin and bombesin produced a significant but partial decrease in avoidance responding; larger doses of these peptides did not produce a greater effect. beta-Endorphin elicited dose-related decrements in avoidance responding. In addition, the effect of neurotensin, but not bombesin or beta-endorphin, was antagonized by simultaneous administration of an equimolar dose of thyrotropin-releasing hormone. Hence, the 3 peptides do not appear to produce decreases in avoidance responding by the same mechanism. Thyrotropin-releasing hormone, luteinizing hormone-releasing hormone, bradykinin, substance P, des-Tyr1-gamma-endorphin and melanotropin inhibiting factor did not significantly affect avoidance responding. These findings, taken together with previous findings, suggest that intracerebroventricular administration of certain endogenous peptides (neurotensin, bombesin and beta-endorphin) may exert neuroleptic-like effects.
 ...
PMID:The effects of neuropeptides on discrete-trial conditioned avoidance responding. 617 91

We have prepared a fluorescent conjugate of porcine calmodulin with 5-(dimethylamino)-1-naphthalene-sulfonyl chloride that is highly sensitive to both calcium binding and protein binding. We have used the fluorescence of this conjugate in addition to the intrinsic peptide fluorescence to show that adrenocorticotropic hormone (ACTH), beta-endorphin, glucagon, and substance P undergo calcium-dependent binding by calmodulin, with competition for common binding sites. The dissociation constants determined in the presence of 0.85 mM CaCl2 and 0.2 N KC1, pH 7.3 at 25 degrees C, range from 1.5 muM to 3.4 muM. The alpha-melanocyte-stimulating hormone, bombesin, and somatostatin also bind, with dissociation constants between 60 muM and 90 muM. Angiotensins I and III, bradykinin, neurotensin, physalaemin, substance P octapeptide, insulin, and Leu- and Met-enkephalin show little or no binding. Sequence comparisons show that the peptides that bind calmodulin well contain regions structurally similar to the recognition sequence for the cAMP-dependent protein kinase and to the sequences surrounding phosphorylated serine residues in several calmodulin binding proteins. This result suggests that modification of calmodulin binding sites in calmodulin-dependent proteins is one of the functions of protein kinase. Calcium has a dual role in peptide binding by calmodulin. The occupation of calcium binding sites having a pK approximately 4 results in a 2-fold increase in peptide binding affinity.
 ...
PMID:Binding of simple peptides, hormones, and neurotransmitters by calmodulin. 618 Jul 61

An antiserum specific for atriopeptin was used to characterize and localize atriopeptin-like immunoreactive material in rat atrium by radioimmunoassay and immunohistochemical techniques. The antiserum recognizes atriopeptin I, atriopeptin III, and alpha-human atrial natriuretic polypeptide, but does not recognize met-enkephalin, cholecystokinin, dynorphin A, bradykinin, substance P, or beta-endorphin. A high content of atriopeptin was found in crude extracts of rat atria, as compared to ventricles, and the atriopeptin-like immunoreactive material was found to be located exclusively in granules within atrial cardiocytes. Fractionation of the immunoreactive material by gel filtration and reverse-phase HPLC revealed the presence of multiple atriopeptins.
 ...
PMID:Characterization and localization of atriopeptin in rat atrium. 624 72


<< Previous 1 2 3 4 5 6 Next >>