Dynorphin A (1-17) was Selective tomicro-Opioid Receptor in Agonist-Stimulated 35S GTPgammaS Binding in Cortical and Thalamic Membranes of Monkey.
10.4097/kjae.2005.48.4.412
- Author:
Heeseung LEE
1
;
Sung Ae LEE
;
Sin Young KANG
;
Dong Yeon KIM
;
Chi Hyo KIM
Author Information
1. Department of Anesthesiology and Pain Medicine, College of Medicine, Ewha Womans University, Seoul, Korea. leehee@ewha.ac.kr
- Publication Type:Original Article
- Keywords:
dynorphin A (1-17);
GTPgammaS;
monkey;
opioid receptor
- MeSH:
Dynorphins*;
Guanosine 5'-O-(3-Thiotriphosphate)*;
Haplorhini*;
Humans;
Macaca mulatta;
Male;
Membranes*;
Naloxone;
Opioid Peptides;
Receptors, Opioid;
Thalamus
- From:Korean Journal of Anesthesiology
2005;48(4):412-416
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Dynorphin A (1-17) is conceived as an endogenous opioid peptide with a high degree of selectivity forkappa- opioid receptor even though it has been reported to sometimes act like amicro- opioid agonist. The aim of this study was to investigate [35S] GTPgammaS binding stimulated activation by dynorphin A (1-17) in the cerebral and thalamic membranes of a rhesus monkey. METHODS: The rhesus monkey (Macaca mulatta, male, n = 1) was euthanized for the preparation of the cerebral and thalamic membranes. Protein concentrations were determined by the Bradford method. In the dynorphin A (1-17)-stimulated [35S] GTPgammaS binding dose-response curve, EC50 (effective concentration 50 nM) and maximum stimulation (% over basal) were determined in the absence or presence of themicro-andkappa-opioid receptor antagonists naloxone (20 nM) and norbinaltorphimine (nor-BNI, 3 nM), respectively. E2078-stimulated [35S] GTPgammaS binding was also determined in the absence or presence ofmicro-andkappa-opioid receptor antagonists in the cortical membrane and compared with dynorphin A (1-17). RESULTS: Values of EC50 and maximum stimulation of dynorphin A (1-17)-stimulated [35S] GTPgammaS binding were as follows: cortex (474 nM/32.0%) and thalamus (423 nM/45.3%). Nor-BNI (3 nM) did not antagonize dynorphin A (1-17)-stimulated [35S] GTPgammaS binding at all in cortical or thalamic membrane, but naloxone (20 nM) produced a 12.2 fold rightward shift of the dynorphin A (1-17)-stimulated [35S] GTPgammaS binding dose-response curve in the thalamic membrane. The EC50 and the maximum stimulation of E2078-stimulated [35S] GTPgammaS binding were 65.6 nM and 22.7%, respectively. In E2078-stimulated [35S] GTPgammaS binding, the dose-response curve was antagonized not by nor-BNI but by naloxone but in the cortical membrane (a 14.2 times rightward shift). CONCLUSIONS: Dynorphin A (1-17) is selective formicro-opioid receptor in agonist-stimulated [35S] GTPgammaS binding in the cortical and thalamic membranes of rhesus monkey.
