G-opioid receptor

Corbett, A., McKnight, S., Henderson, G.. Opioid receptors, http //opioids.com/receptors, 2002. 

Bergevin A, Girardot D, Bourque MJ et al (2002) Presynaptic g-opioid receptors regulate a late step of the secretory process in rat ventral tegmental area GABAergic neurons. Neuropharmacology 42 1065-78... 

In an early study employing autoradiography with [3H]DTLET, 6-opi-oid receptors were found to be chiefly in the olfactory bulb, caudate-putamen, and the cortex, whereas the g opioid receptors were distributed in the caudate-putamen, nucleus accumbens, cingulate cortex, and various thalamic nuclei... 

Methadone is a synthetic g, opioid receptor agonist that is three times as potent as morphine. It is unique in that it has significant bioavailability... 

Figure 7.4. Ligands used to characterize g opioid receptors.

C. On conformational inducing conformational G. Opioid receptors ligands... 

The peptides subtly modified in the side chain at N-terminus residue yielded an opioid with high dual affinities to both 8- and g-opioid receptor types. At present, it appears that the replacement of the Tyr residue by the innatural Dmt analogue in the 5- selective opioid agonist, deltorphin B, produced a peptide with high affinity for both g- and 8-opioid receptors, thereby yielding a 5-opioid receptor ligand which, to all intents and purposes, lacks 5-opioid receptor selectivity. 

While the high affinity for the g-opioid receptor was confirmed in the in vitro pharmacological assay (guinea- pig ileum), in vivo antinociception apparently failed to correlate with high g-opioid receptor activity however, the activity profile of peptide 1 [DMT1] deltorphin B was more closely related to that of the 8- selective opioid peptides 2 (deltorphin B) and 3 (deltorphin C). 

Opioids act on heptahelical G-protein-coupled receptors. Three types of opioid receptors (p, 8, k) have been cloned. Additional subtypes (e.g., pl3 p2, 81 82), possibly resulting from gene polymorphisms, splice variants or alternative processing have been proposed. Opioid receptors are localized and can be activated... 

Opioids ( opioid systems) are thought to exert their antitussive effects by acting as agonists at p- and K-opioid receptors in the CNS. Activation of these receptors activates various G-proteins and leads to the inhibition of... 

The pharmacological and/or adverse effects of a drug can be reversed by co-administration of drugs which compete for the same receptor. For example, an opioid receptor antagonist naloxone is used to reverse the effects of opiates. Drugs acting at the same site with opposite effects also can affect each other, e.g. the reduction in the anticoagulant effect of warfarin by vitamin K. 

Potenza MN, Gold SJ, Roby-Shcmkowitz A, et al Effects of regulators of G protein-signaling proteins on the functional response of the mu-opioid receptor in a mel-anophore-based assay. J Pharmacol Exp Ther 291 482 91, 1999 Quaglio G, Talamini G, Lechi A, et al Study of 2708 heroin-related deaths in northeastern Italy 1985—98 to establish the main causes of death. Addiction 96 1127— 1137, 2001... 

Woody GE, Luborsky L, McLellan AT, et al Psychotherapy for opiate addicts does it help Arch Gen Psychiatry 40 639—645, 1983 Woody GE, McLellan AT, Luborsky L, et al Severity of psychiatric symptoms as a predictor of benefits from psychotherapy the Veterans Administration-Penn study. Am J Psychiatry 141 1172—1177, 1984 Woody GE, McLellan AT, Luborsky L, et al Twelve-month follow-up of psychotherapy for opiate dependence. Am J Psychiatry 144 590-596, 1987 Yabaluri N, Medzihradsky F Down-regulation of mu-opioid receptor by full but not partial agonists is independent of G protein coupling. Mol Pharmacol 52 896-902, 1997... 

Saracibar G, Hernandez ML, Echevarria E, et al Toluene alters mu-opioid receptor expression in the rat brainstem. Ind Health 39 231-234, 2001 Schikler KN, Seitz K, Rice JF, et al Solvent abuse associated cortical atrophy. J Adolesc Health Care 3 37-39, 1982... 

Chao CC, Gekker G, Hu S, Sheng WS, Shark KB, Bu DP, Archer S, Bidlack JM, Peterson PK (1996a) kappa opioid receptors in human microglia downregulate human immunodeficiency virus 1 expression. Proc Natl Acad Sci USA 93 8051-8056 Chao CC, Hu S, Peterson PK (1996b) Opiates, gUa, and neurotoxicity. Adv Exp Med Biol 402 29-33... 

Parenty G, Appelbe S, Milligan G (2008) CXCR2 chemokine receptor antagonism enhances DOP opioid receptor function via allosteric regulation of the CXCR2-DOP receptor heterodimer. Biochem J 412 245-256... 

Tomassini N, Renaud F, Roy S, Loh HH (2004) Morphine inhibits Fc-mediated phagocytosis through mu and delta opioid receptors. J Neuroimmunol 147 131-133 Trillo-Pazos G, Kandanearatchi A, Eyeson J, King D, Vyakamam A, Everall IP (2004) Infection of stationary human brain aggregates with HIV-1 SF162 and IIIB results in transient neuronal damage and neurotoxicity. Neuropathol Appl Neurobiol 30 136-147... 

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