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)

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

The distribution and cellular localization of leu-enkephalin in the gut and pancreas was studied by immunohistochemistry using two different antisera, one specifically directed against leu-enkephalin and the other cross reacting with met-enkephalin. The results were identical with both antisera. In all species examined, enkephalin-immunoreactive material was found in nerves of the smooth muscle, particularly numerous in the myenteric plexus. Here, immunoreactive nerve cell bodies were observed occasionally. In addition, enkephalin-immunoreactive material was demonstrated in gut endocrine cells of chicken, mouse, rat, pig and monkey but not of guinea pig, cat and man. Enkephalin cells were detected also in the exocrine parenchyma of the porcine pancreas. They were rare in the gut of mouse, rat and monkey but numerous in the antrum and duodenum of pig where they were identified as 5-hydroxytryptamine-storing enterochromaffin cells. The enkephalin-containing cells of the porcine antrum and duodenum were defined ultrastructurally by the consecutive semithin/ultrathin section technique. The ultrastructural features were typical of enterochromaffin cells, the most characteristic ones being the irregular shape and high electron density of the cytoplasmic granules. The immunoreactive material was confined to the cytoplasmic granules.
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PMID:Leu-enkephalin-like material in nerves and enterochromaffin cells in the gut. An immunohistochemical study. 9 94

Effect of methionine-, leucine-enkephalin (met-, leu-enkephalin) and substance P on the transmission in mouse vas deferens was studied. Both met- and leu-enkephalin inhibited electrically induced contraction of vas deferens at 10(-8)-10(7) M, met-enkephalin being 1.4 times more active than leu-enkephalin. Nalorphine (10(-6) M) antagonized these effects. Substance P (10(-9)-10(-7) M) had no effect on the contraction. Met- and leu-enkephalin (10(-7)-10(-5) M) decreased the high potassium induced [3H]-norepinephrine release from vas deferens, while substance P (10(-6) M) significantly increased it. Nalorphine (10(-5) M) reversed the inhibitory effect of met-enkephalin. These results indicate that these peptides modify the transmission of sympathetic nerve in mouse vas deferens.
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PMID:Effect of enkephalin and substance P on sympathetic nerve transmission in mouse vas deferens. 20 50

Met-enkephalin can be rapidly separated with high recovery from leu-enkephalin, beta-endorphin, and enkephalin metabolites by high-pressure liquid chromatography on a Dupont SCX column. The technique permits separation of endogenous enkephalins from brain extracts for measurement by opiate-receptor binding assay, immunoassay, or for study of the incorporation of radiolabeled amino acids into enkephalin. Using this technique, met-enkephalin was separated from striatal extracts of rats killed by focused microwave irradiation and quantitated by the opiate-receptor binding assay. The concentration of met-enkephalin in the column eluate was 1.3 micron/g tissue. This value is comparable to that obtained by radioimmunoassay without purification of the extracts.
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PMID:Met-enkephalin: rapid separation from brain extracts using high-pressure liquid chromatography, and quantitation by binding assay. 21 27

Endorphins are peptides with opiate-like action synthesized in various tissue, e.g. in intestine and central nervous system. Exact characterization of opioid-specific receptors and sensitive biological test assays for opioids were prerequisites for the discovery of these substances. Met- and leu-enkephalin were the first endorphins discovered. Both are pentapeptides. One of them, namely met-enkephalin (H-Tyr-Gly-Gyl-Phe-Met-OH) is likely to be a fragment of the peptides alpha- and beta-endorphin, both showing opioid-like actions, as well as of beta-lipotropin, a polypeptide showing no opioid-like activity: all these peptides include the pentapeptide met-enkephalin within their molecules. beta-liportropin and ACTH are likely to be fragments of a common precursor. At least both enkephalins (which are studied better as yet than the other endorphins) are supposed to be formed in the soma of the neuron and transported to the nerve ending, where they are released. They seem to have the function of neuromodulator or even of neurotransmitters. The pharmacological actions of endorphins resemble those of "classical opiates", both having e.g. analgesic effects. Both enkephalins are, among various other brain and spinal cord areas, localized in those areas which seem to be of particular relevance for perception and transmission of pain. They might, under certain conditions, play some part in the regulation of pain perception. Furthermore, they seem to be relevant for some neuroendocrine processes. Their relevance in symptoms of schizophrenic psychoses seems to be more doubtful. In opiate dependence no significant alterations of endorphin concentrations could be observed as yet.
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PMID:[On the physiology and pharmacology of endorphins (author's transl)]. 22 45

Interactions between SP and the enkephalins have bben reported in the CNS, and the possibility of a more peripheral site of interaction has now been investigated. SP (10(-6) - 10(-4) g/ml) induced dose-related contractions of the rabbit isolated aorta, which were resistant to alpha-adrenoceptor blockade (phentolamine, 5 x 10(-6) g/ml). Neither met- nor leu-enkephalin had any intrinsic action on the aorta, but met-enkephalin at 5 x 10(-6) g/ml significantly inhibited responses to SP but not to NE. Morphine (5 x 10(-6) g/ml) potentiated responses to NE, but had no significant effect on responses to SP. It is apparent that SP and met-enkephalin act on a common receptor on vascular smooth muscle, that met-enkephalin has no intrinsic action on this receptor, and that the receptor is morphine-insensitive.
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PMID:The interaction of enkephalins with substance P on vascular smooth muscle. 46 50

The Merkel cells from sinus hair follicles of rats were investigated by immunohistochemistry using different antisera against neuropeptides and gastroenteropancreatic (GEP)-hormones. For the first time it has been demonstrated that Merkel cells exhibit an immunoreactivity towards metenkephalin (methionine-enkephalin). The met-enkephalin immunoreactivity was restricted to Merkel cells and was not found in associated nerve axons or terminals. Denervation of Merkel cells did not affect the met-enkephalin immunoreactivity. Antisera leu-enkephalin (leucine-enkephalin) and other polypeptides did not produce an immunoreaction. The demonstration of met-enkephalin-like immunoreactivity supports the concept that the Merkel cell is a member of the paraneuronal system and a potential neuroreceptor cell.
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PMID:Met enkephalin-like immunoreactivity in Merkel cells. 50 86

Using naloxone as the antagonist, a comparison of pA2 values obtained from the guinea pig ileal longitudinal muscle preparation revealed that both leucine (leu-) enkephalin and methionine (met-) enkephalin can be classified as pure narcotic agonists with pA2 values similar to that of morphine but different from that of nalorphine. In addition, cross tolerance to both met- and leu-enkephal in could be demonstrated on an ileal strip made tolerant to morphine by implantation of morphine pellets to a guinea pig for 72 hours. Pretreatment of a naive muscle strip to three increasing concentrations of leu-enkephalin was found to markedly decrease the IC50 of morphine and to sensitize the ileal strip to naloxone as was evidenced by an increase in the morphine-naloxone pA2 value. Met-enkephalin or morphine pretreatment had no effect on subsequent morphine IC50 determinations but similarly increased the morphine-naloxone pA2 value. These results suggest that although both leu- and met-enkephalin may be classified as pure narcotic agonists, their interaction with morphine on the ileal strip is markedly different. Leu-enkephalin may be an important physiological modulator of narcotic efficacy.
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PMID:Characterization of leucine and methionine enkephalin and their interaction with morphine on the guinea pig ileal longitudinal muscle. 70 20

The presence of substance P (SP) in the amniotic fluid (AF) from 88 obstetric patients was determined with a radioimmunoassay. AF was collected from each patient in EDTA-coated tubes. Cross-reactivity of anti-SP antibody with methionine, met-enkephalin, leu-enkephalin, beta-endorphin, eledoisen and physalemin was less than 1%. The SP levels during the midtrimester were not significantly lower than those of late gestation. Data on the late-gestation group were evaluated further as per the clinical problem. The only statistically significant finding was between the diabetics with fetal maturity and the non-diabetic group. This preliminary study identified the presence of SP in AF in mid and late gestation.
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PMID:Amniotic fluid levels of substance P. 127 66

To extend the knowledge on the central effects of cytokines, we studied the effects of tumor necrosis factor alpha and interleukin-1 alpha on nociceptive thresholds and spontaneous locomotor activity in rats. After central administration, both tumor necrosis factor alpha and interleukin-1 alpha significantly (P < 0.001) increase the nociceptive thresholds as measured by the hot-plate test. Tumor necrosis factor alpha, but not interleukin-1 alpha decreases spontaneous locomotor activity evaluated by the Animex test. The increase in nociceptive thresholds induced by tumor necrosis factor alpha or interleukin-1 alpha is not affected by the opiate receptor antagonist naloxone, or antisera against the endogenous opioids beta-endorphin, met-enkephalin or dynorphin. The analgesic effect of tumor necrosis factor alpha is completely antagonized by anti-IL-1 antibodies. Moreover, the cyclooxygenase inhibitor indomethacin does not antagonize the increase of nociceptive thresholds induced by either cytokine.
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PMID:Central effects of tumor necrosis factor alpha and interleukin-1 alpha on nociceptive thresholds and spontaneous locomotor activity. 130 May 7


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