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)

The inhibition of the tail-flick response induced by beta-endorphin given i.c.v. has been demonstrated to be mediated by the stimulation of epsilon- but not mu-, delta- or kappa-opioid receptors. beta-Endorphin given i.t. also inhibited the tail-flick response. The present studies were designed to determine what types of opioid receptors in the spinal cord were involved in i.t. beta-endorphin-induced tail-flick inhibition. Blockade of kappa-opioid receptors by coadministration of nor-binaltorphimine or Win 44,441-3 with beta-endorphin given i.t. dose dependently inhibited i.t. beta-endorphin-induced inhibition of the tail-flick response. Blockade of mu-opioid receptors by i.t. coadministration of D-Phe-Cys-Tyr-D-Try-Orn-Thr-Pen-Thr-NH2 with beta-endorphin blocked i.t. beta-endorphin-induced inhibition of the tail-flick response. I.t. injection of delta-opioid receptors antagonists, ICI 174,864 and naltrindole, or epsilon-opioid receptor antagonist, beta-endorphin-(1-27), did not affect inhibition of the tail-flick response induced by beta-endorphin given i.t. Blockade of alpha 2-adrenoceptors and 5-HT receptors by i.t. injection of yohimbine and methysergide, respectively, also did not affect inhibition of the tail-flick response induced by beta-endorphin given i.t. The results indicate that the inhibition of the tail-flick response induced by beta-endorphin given i.t. is mediated by the stimulation of kappa- and mu-opioid receptors but not delta- and epsilon-opioid receptors, alpha 2-adrenoceptors or 5-HT receptors.
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PMID:The tail-flick inhibition induced by beta-endorphin administered intrathecally is mediated by activation of kappa- and mu-opioid receptors in the mouse. 131 80

Systemic injections of opiate agonists were made in male rats to elucidate the involvement of multiple opioid receptors in the stress response. As an index of activity in the hypothalamic-pituitary-adrenocortical axis, plasma corticosterone was measured by radioimmunoassay. Rats were injected with ethylketocyclazocine (EKC), U50488H, MR2034, bremazocine or tifluadom and sacrificed 1 hr later. These kappa agonists produced potent, dose-dependent, stereospecific increases in plasma corticosterone levels at doses far below those needed to elicit analgesia. These effects were reversed by opiate antagonists, naloxone or Win 44441-3, which by themselves caused dose-dependent decreases in plasma corticosterone. Animals made tolerant to the prototype kappa agonist, U50488H, showed an attenuated response to an acute injection of the drug. However, when animals made tolerant to morphine were injected acutely with U50488H, the drug caused a dramatic increase in corticosterone levels. In hypophysectomized rats, U50488H and L-EKC did not increase plasma corticosterone. The agonist/antagonists, butorphanol and cyclazocine, when injected, behaved like kappa agonists and increased plasma corticosterone levels potently. The mu opiates, morphine and etorphine, also had similar effects but were less potent and efficacious than the kappa agonists. The delta agonist D-Ala-D-Leu enkephalin showed similar results, confirming a mu and delta opioid input into the hypothalamic-pituitary-adrenocortical axis. There were concomitant increases in plasma adrenocorticotropin in morphine-, D-Ala-D-Leu enkephalin-, L-EKC- and U50488H-treated rats which were also seen in adrenalectomized rats. D-EKC and D-cyclazocine, which bind to sigma sites, had no effect on corticosterone.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Kappa opiate agonists modulate the hypothalamic-pituitary-adrenocortical axis in the rat. 301 37

Changes of endogenous opioid peptide system by pain stimuli were examined using adjuvant-induced arthritic rats. Following the 5th day after adjuvant inoculation, met-enkephalin (ME)-like peptide content in plasma decreased, while after the 12th day, the peptide content increased in adrenal medulla. A significant correlationship was found between pain threshold and plasma ME-like peptide content. Y-20003, a new nonsteroidal agent without inhibition of prostaglandin biosynthesis, showed an analgesic effect which was significantly antagonized by naloxone or Win 44,441-3, suggesting that endogenous opioid peptide system may be involved in the analgesic mechanism of Y-20003.
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PMID:Influence of Y-20003, an analgesic agent, on the endogenous opioid peptide system in rats. 312 39