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1.
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This review presents the generalized literature data and the results of our own research of the nonopioid effect of β-endorphin, an opioid neuropeptide interacting not only with opioid but also with nonopioid (insensitive to the opioid antagonist naloxone) receptors. The roles of the hormone and its receptors in regulation of the immune, nervous, and endocrine systems are discussed. The effect of neuromediator on the immune system mediated by both opioid and nonopioid receptors is considered in detail. The data on distribution and function of the nonopioid β-endorphin receptor in human and animal organisms are presented. All available data on the characteristics of the nonopioid β-endorphin receptor obtained by means of radioligand analysis are given. The discussed information is supposed to extend our conceptions of the role of β-endorphin in mammals and to be of extensive use in medicine and pharmacology.  相似文献   

3.
Human β-endorphin (15 μg) administered intracisternally increased concentrations of serotonin (5HT) and its metabolite, 5-hydroxyindoleacetic. acid (5-HIAA), in brain stem and hypothalamus and decreased 5-HIAA concentrations in hippocampus. These data are compatible with the hypothesis that β-endorphin increases 5HT turnover in brain stem and hypothalamus and decreases 5HT turnover in hippocampus. β-endorphin increased in brain stem and hypothalamus and decreased in hippocampus the rate of pargyline-induced decline of 5-HIAA. β-endorphin decreased the rate of pargyline-induced accumulation of 5HT in all these brain regions. The probenecid-induced accumulation of 5-HIAA in brain stem was decreased by β-endorphin. These data are compatible with the hypothesis that β-endorphin increases release of 5HT from neurons in brain stem and hypothalamus and decreases release of 5HT from neurons in hippocampus. The data require further a hypothesis that β-endorphin either decreases 5HT reuptake in these three brain regions or increases 5-HIAA egress from brain.  相似文献   

4.
Experiments were performed to establish the development of cross tolerance between morphine and the C-terminal fragment of porcine β-lipotropin /LPH61–91, β-endorphin/ in rats. Repeated intracerebroventricular /ICV/ or peripheral administration of morphine induced tolerance both to morphine and β-endorphin. The tolerance induced by ICV administration of morphine was more pronounced than in the case of peripheral application. The results give support to the theory that at least in part similar sites and mechanisms are involved in the analgesic activity of morphine and the endorphins.  相似文献   

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6.
The opioid system regulates food choice, consumption, and reinforcement processes, especially for palatable meals such as fatty food. β-Endorphin is known as an endogenous opioid peptide produced in neurons of the hypothalamus. In this study, we found that Intralipid (fat emulsion) ingestion increased c-fos expression in β-endorphin neurons. However, intragastric infusion of Intralipid only slightly increased c-fos expression 2h after infusion. Further, dissection of glossopharyngeal nerve, innervating posterior tongue taste buds, partially but significantly decreased the Intralipid-induced c-fos expression. These results indicate that mainly the orosensory stimulation from fat may activate β-endorphin neurons, thereby promoting β-endorphin release.  相似文献   

7.

Background

TRPA1 has been implicated in both chemo- and mechanosensation. Recent work demonstrates that inhibiting TRPA1 function reduces mechanical hypersensitivity produced by inflammation. Furthermore, a broad range of chemical irritants require functional TRPA1 to exert their effects. In this study we use the ex-vivo skin-nerve preparation to directly determine the contribution of TRPA1 to mechanical- and chemical-evoked responses at the level of the primary afferent terminal.

Results

Acute application of HC-030031, a selective TRPA1 antagonist, inhibited all formalin responses in rat C fibers but had no effect on TRPV1 function, assessed by capsaicin responsiveness. Genetic ablation experiments corroborated the pharmacological findings as C fibers from wild type mice responded to both formalin and capsaicin, but fibers from their TRPA1-deficient littermates responded only to capsaicin. HC-030031 markedly reduced the mechanically-evoked action potential firing in rat and wild type mouse C fibers, particularly at high-intensity forces, but had no effect on the mechanical responsiveness of Aδ fiber nociceptors. Furthermore, HC-030031 had no effect on mechanically-evoked firing in C fibers from TRPA1-deficient mice, indicating that HC-030031 inhibits mechanically-evoked firing via a TRPA1-dependent mechanism.

Conclusion

Our data show that acute pharmacological blockade of TRPA1 at the cutaneous receptive field inhibits formalin-evoked activation and markedly reduces mechanically-evoked action potential firing in C fibers. Thus, functional TRPA1 at sensory afferent terminals in skin is required for their responsiveness to both noxious chemical and mechanical stimuli.  相似文献   

8.
The behavioral effects of β-endorphin, enkephalin analogs, morphine and etorphine were briefly compared. In the tail-flick test in mice and in the wet shake test in rats, β-endorphin and D-Ala2-D-Leu5-enkephalin had equal antinociceptive activity; D-Ala2 -Met-enkephalinamide and D-Leu5-enkephalin were less active. The order of activity of the enkephalin analogs and opiate alkaloids for stimulating locomotor activity in mice paralleled their analgesic activities; β-endorphin, however, had only minimal stimulatory actions. Morphine sulfate, 50 μg injected into the periaqueductal gray, produced hyperactivity but this effect was not observed with etorphine or opioid peptides. By contrast, “wet dog” shakes was observed with the opioid peptides but not with either opiate alkaloid. These heterogenous behavioral responses, which were all antagonized by naloxone, indicate that multiple types of receptors mediate the effects of opiates in the central nervous system.  相似文献   

9.
Human β-endorphin produced a potent antinociceptive response as estimated by the tail-flick test in rats after intraventricular injection. On a molar basis, the peptide was 21 times more potent than morphine and in addition, the peptide produced morphine-like catatonia and hypothermia. These responses were blocked by naloxone. Repeated injections of the peptide induced tolerance to analgesic response, catatonia and hypothermia. Cross tolerance to morphine was also observed.  相似文献   

10.
R.L. Reid  S.S.C. Yen 《Life sciences》1981,29(25):2641-2647
β-endorphin administration via constant infusion inhibited the release of growth hormone (GH) and augmented the release of prolactin (PRL) induced by arginine in normal female subjects. Although β-endorphin infusion also induced hyperglycemia, the increment in plasma glucose was insufficient to account for the observed suppression of arginine-initiated GH release. These studies demonstrate that β-endorphin influences, in opposed directions, the secretion of PRL and GH in women.  相似文献   

11.
Summary A peptide immunochemically related to -endorphin was detected in some LH-RH neurons of the fetal human hypothalamus by comparison of adjacent sections stained for -endorphin and for LH-RH. In the same section, by successive staining and after antibody elution, both peptides were again revealed in the same neuron. The significance of the presence of the -endorphin-like material in LH-RH neurons is discussed.  相似文献   

12.
Summary The peroxidase-antiperoxidase immunocytochemical technique was used to identify the ACTH/endorphin cells in the porcine pituitary at the ultrastructural level and to determine the precise subcellular localization of the pro-ACTH/endorphin fragments. The cells display different aspects: 1) large, regular shapes with numerous and large secretory granules; 2) small, irregular and angular shapes with small granules aligned along the periphery of the cell; and 3) intermediate forms. The presence of and -endorphin not only in the same cells but also in the same secretory granules that contain ACTH and -LPH clearly indicates that both the precursor or its fragments and the abovementioned peptides are stored in the same granules and released simultaneously by the corticotropic cells. The presence of FSH in some corticotropic cells is also discussed.Abbreviations used in this Article ACTH corticotropin - -MSH -melanotropin (ACTH I–I3) - CLIP corticotropin-like intermediate lobe peptide (ACTH 18–39) - -LPH -lipotropin - -MSH -melanotropin (-LPH 41–58); -endorphin (-LPH 61–91); -endorphin (-LPH 61–76)  相似文献   

13.
In view of the close structural similarity of the pro-opiocortin fragment γ-MSH and of ACTH/MSH type peptides, the behavioral profile of γ-MSH was explored. Attention was first focussed on behavioral procedures in which ACTH/MSH related neuropeptides have been found effective. Using different procedures to test avoidance behavior, it was found that γ-MSH and ACTH-like neuropeptides had opposite effects. In this respect the activity of γ-MSH resembles that of opiate antagonists rather than that of β-endorphin. Accordingly, ACTH1–24-induced excessive grooming which is blocked by opiate antagonists, is attenuated by γ-MSH. In addition, γ-MSH injected into the periaqueductal gray matter of the brainstem of opiate naive rats elicited symptoms reminiscent of those seen after opiate withdrawal. γ-MSH attenuated more or less several effects of intracerebroventricularly administered β-endorphin (e.g. antinociception, hypothermia, α-MSH release) and decreased acquisition of heroin self-administration. Although γ-MSH at rather high doses displaced naloxone from its specific binding sites in brain homogenates, it did not interfere with β-endorphin-induced effects on in vitro muscle preparations (guinea pig ileum, rat rectum). Interestingly, γ-MSH induced relaxation of the rat rectum in vitro. It is postulated that γ-MSH may attenuate β-endorphin-induced effects by acting via γ-MSH receptor sites (functional antagonism), although a pharmacological antagonism cannot be excluded as yet.  相似文献   

14.
The isolation of a 31-amino acid peptide from human pituitary glands has been described. Its amino acid sequence has been proposed to be identical to the sequence of the carboxyl-terminal 31 amino acids of human β-lipotropin. The peptide, designated as βh-endorphin, possesses significant opiate activity.  相似文献   

15.
Peripheral plasma patterns of cortisol and β-endorphin were compared around weaning in primiparous sows. Blood samples for hormone analysis were collected repeatedly on the day before weaning, on the day of weaning and on the day after weaning. Peak cortisol and β-endorphin levels occurred shortly after weaning on the day of weaning. Cortisol concentration on the day of weaning was greater (P < 0.001) than on the day before weaning, which in turn was higher (P < 0.05) than on the day after weaning. β-Endorphin concentrations on the day before weaning and on the day of weaning were similar, but were greater (P < 0.01) on both these days than on the day after weaning. Overall, cortisol and β-endorphin patterns followed a similar trend, which was more marked on the day before weaning and on the day of weaning than on the day after weaning. Pearson's correlation coefficients for peripheral plasma cortisol and β-endorphin secretion were 0.61 (P < 0.001) on the day before weaning, 0.63 (P < 0.001) on the day of weaning and 0.15 (P < 0.13) on the day after weaning. The present study indicates that suckling and weaning are stressful stimuli during which the peripheral plasma concentrations of cortisol and β-endorphin follow a similar trend.  相似文献   

16.
The effect of intraventricular administration of β-endorphin on pulsatile LH release in castrated conscious rats was studied. The administration of 1 μg of β-endorphin into the lateral ventricle inhibited pulsatile discharge of LH secretion. Intravenous administration of naloxone blocked the suppressive effect of β-endorphin on LH release. These results suggest a possible role of β-endorphin, in addition to Met5-enkephalin, in the control of LH release in male rats.  相似文献   

17.
Insights into the three-dimensional structure of hormone fibrils are crucial for a detailed understanding of how an amyloid structure allows the storage of hormones in secretory vesicles prior to hormone secretion into the blood stream. As an example for various hormone amyloids, we have studied the endogenous opioid neuropeptide β-endorphin in one of its fibril forms. We have achieved the sequential assignment of the chemical shifts of the backbone and side-chain heavy atoms of the fibril. The secondary chemical shift analysis revealed that the β-endorphin peptide adopts three β-strands in its fibril state. This finding fosters the amyloid nature of a hormone at the atomic level.  相似文献   

18.
The present study compared the effects of partial sleep deprivation and the effects of an intake of a hypnotic compound (zolpidem) prior to bedtime, on sleep and on hormonal and metabolic adaptations to subsequent exercise. Sleep deprivation consisted of a delayed bedtime and an early getting-up time. Eight young subjects, who slept well and were highly trained athletes, were enrolled in this study. Sleep was recorded polygraphically and the following afternoon exercise was performed on a cycle ergometer for 30 min at 75% of maximal oxygen consumption (VO2max) after a 10-min warm up. Met-enkephalin, beta-endorphin, cortisol, and lactate concentrations were measured at rest and during exercise. The data obtained after experimental sleep, with and without medication were compared with those obtained in the reference condition with normal sleep. Both types of sleep reduction decreased the total sleep time, stage 2 sleep, and rapid eye movement sleep, whereas zolpidem administration did not modify either the duration of sleep or the sleep stages. After the reference night, plasma met-enkephalin did not show any significant change at the end of the submaximal exercise, whereas beta-endorphin, cortisol, and lactic acid concentrations increased significantly in all subjects. The changes in concentration in beta-endorphin were significantly related to the changes in cortisol (r = 0.78; P less than 0.01) and to the changes in plasma lactic acid (r = 0.58; P less than 0.05). Cortisol concentrations were also related to lactic acid values (r = 0.94; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
The role of the serotonergic mechanism in the regulation of β-endorphin (β-EP) and adrenocorticotropin (ACTH)-like immunoreactivity in plasma was investigated. Increases in β-EP and ACTH-LI produced by quipazine maleate (QPZ), a serotonergic agonist, 1 hr after injection could be completely prevented by the serotonin (5-HT) antagonist, cinanserin (CIN), which when injected alone, decreased basal plasma concentrations of both β-EP-LI and ACTH-LI. Concurrent injections of L-5-HTP with the 5-HT reuptake inhibitor, fluoxetine, produced an additive increase in plasma β-EP-LI 1 hr after injection. Injection of the 5-HT antagonist, cyproheptadine, significantly decreased plasma β-EP-LI. Stress by immobilization for 30 min or exposing the rats to 40° ± 1°C for 30 min produced an approximate 4-fold increase in plasma β-EP-LI and ACTH-LI, which was potentiated by I.P. injections of fluoxetine. Furthermore, the stress induced increases in plasma concentrations of β-EP-LI and ACTH-LI were significantly reduced by the serotonin antagonists metergoline and cinanserin. These results suggest that 5-HT is a potent stimulator of both β-EP and ACTH release and the increase in plasma concentrations of ACTH and β-EP induced by stress are probably mediated, at least in part, by central serotonergic mechanisms.  相似文献   

20.
A double antibody radioimmunoassay technique for γ-endorphin has been developed. The antisera have been raised in rabbits against synthetic γ-endorphin coupled to bovine serum albumin by carbodiimide. The best antibody has a working titer of 135,000 and can detect less than 9 pg of peptide. The usable range of the standard curve is between 9 to 2400 pg. This antiserum probably binds the Glu8-Leu17 region of γ-endorphin and shows only weak cross-reactivity with α-endorphin, β-endorphin and β-lipotropin. Parallelism is observed between the standard curve and the inhibition curves obtained with rat neurohypophysis-pars intermedia extracts or rat plasma.  相似文献   

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