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

The involvement of D2-dopamine receptors in the antinociceptive action of B-HT 920 (2-amino-6-allyl-5,6,7,8-tetrahydro-(4H) thiazolo-(4,5d)-azepine) has been investigated in mice. B-HT 920 (0.1-2.0 mg kg-1) and apomorphine (0.1-2.0 mg kg-1) produced a dose-dependent increase in tail flick latency. Analgesia induced by apomorphine was blocked by the D2-antagonist, haloperidol (1 mg kg-1) but not by the opioid antagonist, naloxone (1 mg kg-1). The antinociceptive action of B-HT 920 was potentiated by the D1-agonist SKF 38393 (5 mg kg-1), an action antagonized by haloperidol. The selective alpha 2-adrenoceptor blocking drug yohimbine (1 mg kg-1) and naloxone (1 mg kg-1) blocked the antinociceptive action of B-HT 920 (1 mg kg-1). Haloperidol, however, failed to modify the B-HT 920-induced increase in tail flick latency. B-HT 920 and apomorphine reversed reserpine (2 mg kg-1) 4 h-induced hyperalgesia. The reversing action of apomorphine was blocked by haloperidol but not by yohimbine. Thus, a role of alpha 2-adrenoceptors and D2-dopamine receptors is postulated in the antinociceptive action of B-HT 920.
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PMID:Alpha 2-adrenoceptor- and D2-dopamine receptor-mediated analgesic response of B-HT 920. 167

The interaction between electroacupuncture and an N-methyl-D-aspartic acid (NMDA) receptor antagonist, (DL-2-amino-5-phosphonopentanoic acid; AP5), or an (+/-)-alpha-Amino-3-hydroxy-5-methylisoxazole-4-propionic acid/kainite (AMPA/KA) receptor antagonist, (6,7-dinitroquinoxaline-2,3 (1H,4H); DNQX) administered intrathecally on carrageenan-induced thermal hyperalgesia and spinal c-Fos expression was investigated. The latency of paw withdrawal (PWL) from a thermal stimulus was used as a measure of hyperalgesia in awake rats. Intrathecal (i.t.) injection of 1 and 10 nmol AP5, but not DNQX, markedly increased the PWL of the carrageenan-injected paw. At a dose of 100 nmol, either AP5 or DNQX significantly increased the PWL of carrageenan-injected paw, with AP5 being more potent. The PWLs of the non-injected and normal saline (NS)-injected paws were not detectably affected by the administration of NMDA or AMPA/KA receptor antagonists at the doses tested. Unilateral electroacupuncture stimulation of the 'Zu-San-Li' (St 36) and 'Kun-Lun' (UB 60) acupuncture points (60 and 2 Hz alternately, 1-2-3 mA) contralateral to the carrageenan-injected paw significantly elevated the PWLs of carrageenan- and NS-injected paws. Although neither i.t. injection of 0.1 nmol AP5 nor 1 nmol DNQX alone had an effect on the PWL of the carrageenan- and NS-injected paws, both significantly potentiated electroacupuncture-induced analgesia in carrageenan-injected rats, especially 0.1 nmol AP5. Fos expression evoked by intraplantar (i.pl.) injection of carrageenan was examined in the spinal cord with immunohistochemical methods. Three hours after i.pl. injection of carrageenan, the number of Fos-like immunoreactive (Fos-LI) neurons was significantly increased in all the layers of the ipsilateral spinal cord at L(4-5), with the highest density in laminae I-II and V-VI. Intrathecally pre-administered AP5 (10 nmol) or DNQX (100 nmol) significantly reduced the total number of carrageenan-induced Fos-LI neurons. The reduction was most apparent in laminae I-II and IV-V. Similarly, following bilateral electroacupuncture stimulation of the 'Zu-San-Li' and 'Kun-Lun' acupuncture points, the numbers of carrageenan-induced Fos-LI neurons in laminae I-II and V-VI were also markedly reduced. When a combination of electroacupuncture with 10 nmol AP5 or 100 nmol DNQX was used, the level of Fos expression in the spinal cord induced by carrageenan was significantly lower than electroacupuncture or i.t. injection of AP5 or DNQX alone. These results demonstrate that electroacupuncture and NMDA or AMPA/KA receptor antagonists have a synergetic anti-nociceptive action against inflammatory pain. Furthermore, this study supports the idea that both NMDA and AMPA/KA receptors are involved in spinal nociceptive transmission in carrageenan-inflamed rats, with the former more preferentially mediating transmission of nociceptive information from cutaneous tissue.
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PMID:Excitatory amino acid receptor antagonists and electroacupuncture synergetically inhibit carrageenan-induced behavioral hyperalgesia and spinal fos expression in rats. 1240 29