Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a previous work (4), it has been described that a noxious visceral stimulation through the intraperitoneal injection of acetic acid (ipAA) induced a transient and low magnitude increase in tail-flick latencies, but a marked increase in the threshold for vocalization and hot-plate latencies. In the present work, this phenomenon of hypoalgesia through counter-irritation was investigated in intact rats with or without pretreatment with the potent serotonin depletor parachlorophenylalanine (pCPA). Three behavioural tests were performed. In two tests (tail flick, vocalization induced by transcutaneous electrical stimulation of the tail), pCPA pretreatment induced an increase of baseline levels, before IP injection of the allogenic agent (ipAA). In the third test, pCPA pretreatment had no effects on jump latencies. Parachlorophenylalanine pretreatment had no effect upon hypoalgesic actions of IP injected AA in all three tests. These results are discussed in terms of pCPA's differential effects upon basal nociception and analgesia induced by various heterotopic nociceptive stimulations.
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PMID:Hypoalgesia induced by counter-irritation is not affected by pCPA pretreatment. 214 Jan 96

It is now well established that compounds classified as kappa opioids can, in circumstances where they produce no measurable agonist effects, antagonize the actions of mu opioids. Largely on the basis of studies in vitro, beta-funaltrexamine (beta-FNA) has been classified as a reversible kappa agonist and long acting mu antagonist. The present study investigated the possibility that the mu antagonist profile of this compound could be related to its kappa agonist actions. We used two tests of analgesia (the acetic acid writhing test and the hot-water tail-flick test) and selective kappa agonists and antagonists given at supraspinal and spinal sites in mice. Intrathecal (i.t.) administration of beta-FNA, but not the selective kappa agonist U50,488H, produced long-lasting and dose-related analgesia in the writhing test for periods up to 48 hr after a single dose. In contrast, i.t. beta-FNA had no agonist actions in the tail-flick test. The kappa antagonist, nor-binaltorphimine (nor-BNI) produced no agonist effects in either analgesic test when given i.t. In the writhing test, nor-BNI produced a rightward displacement of the beta-FNA dose-response line regardless of whether beta-FNA was given 10 min or 4 hr before testing, indicating that i.t. beta-FNA was acting as a kappa agonist in this test. As both i.t. morphine and beta-FNA are active in the writhing test, the antagonist actions of i.t. beta-FNA could be evaluated only in the tail-flick test. beta-FNA, but not nor-BNI, blocked the effects of i.t. morphine in the tail-flick test.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Mu antagonist and kappa agonist properties of beta-funaltrexamine (beta-FNA) in vivo: long-lasting spinal analgesia in mice. 215 86

The purpose of this study was to determine whether sensitivity to nitrous oxide analgesia was altered by chronic ethanol exposure. Control mice exposed to 25%, 50%, and 75% nitrous oxide in oxygen demonstrated a concentration-related analgesic effect, as measured by the acetic acid abdominal constriction test. Other mice previously exposed to ethanol vapors for 72 h exhibited a significantly reduced sensitivity to nitrous oxide analgesia. The dose-response curve of the chronic ethanol-exposed group was shifted to the right of that of the control mice. These findings suggest the possibility that subjects with a history of alcohol abuse might have reduced responsiveness to nitrous oxide in a clinical setting.
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PMID:Influence of chronic ethanol exposure on nitrous oxide analgesia in mice. 221 13

Sanbi Rebao (contain 32 components, such as Radix Aconiti, Rhizoma Chuanxiong, Semen Strychni, Radix Glycyrrhizae, Radix Angelicae sinensis, Radix Ledebouriellae, Fructus Evodiae, borneolum syntheticum, etc.) had antagonistic action on the ear swollen response induced by croton oil and on the ear inflammation reaction caused by dimethylphenylene in mice. It could decrease significantly the response rate of turning its body induced by acetic acid, increase the pain threshold caused by warm, reduce the surface seepage of injure skin and accelerate the wound recovery. The above results showed Sanbi Rebao possessed the roles of dephlogisticate, analgesia and promoting wound recovery, Besides these, clinic research indicated that effective rate of Sanbi Rebao on pain or numbness caused by cold, damp and wind (rheumatism) was 97%.
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PMID:[Main pharmacological roles and clinical curative effect of sanbi rebao]. 226 44

Flavone and 10 hydroxy and glucoside flavone derivatives were synthesised. They were tested for their analgesic effect in mice employing acetic acid-induced writhing and tail immersion methods. Subcutaneously all the tested compounds exhibited significant analgesic activity with varying potencies in both assay models. The activity of flavone and its 5-; 7-; 2'-; 5,7- and 7,8-hydroxy derivatives apparently involves an opiate-like mechanism, since their activity was reversed by naloxone pretreatment. It is suggested that flavonoid substances may utilise more than one mechanism in eliciting analgesia.
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PMID:Analgesic activity of certain flavone derivatives: a structure-activity study. 232 11

The possible involvement of central serotonergic pathways in the mechanism of action of nefopam was investigated in male albino mice. Nefopam (15 mg/kg i.p.) did not alter the concentration of serotonin or its metabolite 5-hydroxyindole acetic acid in frontal cortex or spinal cord. Lesions of the ascending serotonergic pathways were made by systemic administration of p-chloroamphetamine (PCA). Serotonin depletion in all serotonergic systems was obtained by means of p-chlorophenylalanine (PCPA). Two different nociceptive assays were used, the formalin test and the increasing temperature hot plate test. PCPA pretreatment significantly reduced the effect of nefopam (15 mg/kg) in the formalin test. In contrast, nefopam-induced analgesia was not affected by PCA pretreatment, either in the formalin test or in the increasing temperature hot plate test. In conclusion, the data suggest that descending serotonergic pathways are involved in nefopam-induced antinociception.
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PMID:Involvement of central serotonergic pathways in nefopam-induced antinociception. 244 3

The possible involvement of central serotonergic pathways in the mechanism of action of orphenadrine citrate was investigated in male albino mice. Orphenadrine (20 mg/kg) did not alter the concentration of 5-hydroxytryptamine (5-HT) or its metabolite 5-hydroxyindole acetic acid in the frontal cortex or spinal cord, nor did it, in moderate concentrations, inhibit the uptake of [14C]5-HT, [3H]noradrenaline ([3H]NA) or [3H]dopamine ([3H]DA) into crude synaptosomal preparations from the cortex. The antinociceptive effect of orphenadrine was studied in the formalin test and in the increasing temperature hot plate test. No sensorimotor impairment was observed for doses of 30 mg/kg or lower. A general depletion of serotonin by means of p-chlorophenylalanine significantly reduced the effect of orphenadrine in both tests, while lesion of the ascending serotonergic systems by means of p-chloroamphetamine did not affect the analgesia. It is concluded that the antinociceptive effect of orphenadrine may be mediated in part via the raphe-spinal serotonergic systems.
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PMID:Mechanisms of orphenadrine-induced antinociception in mice: a role for serotonergic pathways. 246 92

The contribution of opioid receptor to lappaconitine (LA) induced analgesia was investigated by in vivo and in vitro methods. The antagonistic effects of naloxone (NLX) on the analgesic actions of LA (s.c.) and morphine (MOR, s.c.) were determined by the tail pressure method, the hot plate method and the acetic acid-induced writhing method in mice. The ED50 values of MOR in the absence of NLX were 3.82, 0.50 and 0.33 mg/kg, respectively, but in the presence of NLX, the analgesic effect of MOR was decreased and the ED50 values were changed to 41.6, 4.40 and 5.97 mg/kg, respectively. However, NLX did not affect the analgesic activity of LA. The ED50 values of LA in the three methods were 9.12, 3.34 and 1.70 mg/kg in the absence of NLX and 12.1, 4.19 and 2.88 mg/kg in the presence of NLX, respectively. The inhibitory effect of the LA on the electrically evoked contractions of isolated guinea-pig ileum was weaker than that of MOR, and differently from MOR, its effect was not antagonized by NLX. Additionally, LA did not abolish the electrically evoked contractions of isolated rabbit and mouse vas deferens. In conclusion, the results suggest that the opioid receptor was not involved in the analgesic activity of LA.
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PMID:Pharmacological studies of lappaconitine. Occurrence of analgesic effect without opioid receptor. 253 50

Sulfated cholecystokinin octapeptide (CCK-8; Asp-Tyr-SO3H-Met-Gly-Trp-Met-Asp-Phe-NH2) produced analgesia in mice when administered i.c.v. and tested in the acetic acid-induced writhing assay. The ED50 was found to be 0.03 nmol/mouse which was about 3, 24 and 714 times more potent than morphine. [D-Pen2,D-Pen5]enkephalin and U50,488H [trans-(+/-)-3,4-dichloro-N-methyl-N-[2-(1-pyrolidinyl)cyclohexyl] benzeneacetamidel], respectively. When administered i.t., CCK-8 produced partial analgesia of up to 22 to 23% at low doses ranging from 15 to 60 ng/mouse and hyperalgesia at doses over 120 ng/mouse. Naloxone, an opioid antagonist, inhibited the analgesia induced by CCK-8 (i.c.v. and i.t.) but potentiated hyperalgesia induced by CCK-8 (i.t.). Apparent pA2 value for CCK-8 (i.c.v.) against naloxone (s.c.) was 5.88 which was significantly different from those for morphine-naloxone and U50,488H-naloxone but was not significantly different from that for [D-Pen2,D-Pen5]enkephalin-naloxone. Studies using highly selective opioid antagonists showed that CCK-8-induced analgesia was significantly antagonized by the delta receptor antagonist, ICI154,129 [(Allyl)2-Tyr-gly-gly-psi-(CH2S)-Phe-Leu] but not by beta-funaltrexamine, a highly selective mu receptor antagonist or nor-binaltorphimine, a highly selective kappa receptor antagonist. Opioid receptor binding study using [3H]-[D-Ala2,D-Leu5]enkephalin (+unlabeled [D-Ala2,MePhe4,Gly-ol5]enkephalin) in mouse brain membrane preparations revealed that there were no changes in the maximum binding or Kd of delta opioid binding sites in the presence of CCK-8 (1 microM) in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Indirect involvement of delta opioid receptors in cholecystokinin octapeptide-induced analgesia in mice. 255 28

Selectivity for opioid receptor subtypes of enkephalin analogues (KK-1, -2, -3 and -4) of Tyr moiety on the N-terminal, and Phe-ol group on the C-terminal, connected with the methylene group (n = 1-4) were examined in isolated smooth muscle preparations and in the analgesic effect in mice. In the longitudinal muscle preparations of guinea pig ileum (GPI), morphine, U-50488H and all the enkephalin analogues inhibited electrically evoked contractions, and the inhibitory effects of morphine, KK-1, KK-2 and KK-3 were antagonized by naloxone with relatively high pA2 values, while that of U-50488H and KK-3 were preferentially antagonized by norbinaltorphimine. In the rabbit vas deferens preparations (RVD), on the other hand, U-50488H, KK-3 and KK-4 showed weak inhibitory effects and the inhibition of U-50488H and KK-3 were antagonized by norbinaltorphimine. By intracerebroventricularly (i.c.v.) injection, enkephalin analogues produced analgesia in the acetic acid (AcOH) writhing test, and the effect of KK-1 and KK-2 as well as morphine was antagonized by 1 mg/kg naloxone, while those of U-50488H and KK-3 were sensitive to 1 mg/kg Mr2266. In conclusion, enkephalin analogues with a short methylene chain between the functional groups, KK-1 and KK-2, mainly exert their effect through opioid mu-receptors, while those of longer chain, KK-3 and KK-4, act through kappa-receptors preferentially, and KK-3 is situated in the alternating point of the selectivity for mu- and kappa-receptors.
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PMID:Selectivity for opioid receptor subtypes of enkephalin analogues in isolated smooth muscle and in the analgesic effect in mice. 255 86


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