TY - JOUR
T1 - Resolution in the receptor binding of putative μ and κ opiates
AU - Medzihradsky, Fedor
AU - Dahlstrom, Patricia J.
AU - Woods, James H.
AU - Fischel, Steven V.
AU - Mitsos, Stephanie E.
N1 - Funding Information:
This work was supported in part by USPHS Grant
PY - 1984/5/28
Y1 - 1984/5/28
N2 - Conditions for the stereospecific binding of 3H-ethylketocyclazocine and 3H-etorphine were established in membranes from rat and pigeon brain. In displacing the specific binding of the radiolabeled ligands, putative μ and κ opiates displayed different sensitivity toward sodium. In membranes from both species, the ratio of the sodium responses exhibited by a given drug in displacing 3H-ethylketocyclazocine and 3H-etorphine, respectively, ("double sodium ratio" = DSR) distinguished between μ and κ opiates. Compounds characterized on the basis of their pharmacological effects as κ opiates had DSR values between 0.3 and 2.2, regardless of their nature as agonists or antagonists. In contrast, the DSR for μ opiates ranged from 3.4 to 11. In rat brain membranes, UM 1382 (U-50, 488, a compound with pronounced κ activity) exhibited a DSR of 0.3, while the corresponding value for morphine was 7.4. Dynorphin-(1-13) had a DSR of 1. Within each of the two groups, the simple sodium ratio continued to serve as an index for the agonist or antagonist property of the tested opiates.
AB - Conditions for the stereospecific binding of 3H-ethylketocyclazocine and 3H-etorphine were established in membranes from rat and pigeon brain. In displacing the specific binding of the radiolabeled ligands, putative μ and κ opiates displayed different sensitivity toward sodium. In membranes from both species, the ratio of the sodium responses exhibited by a given drug in displacing 3H-ethylketocyclazocine and 3H-etorphine, respectively, ("double sodium ratio" = DSR) distinguished between μ and κ opiates. Compounds characterized on the basis of their pharmacological effects as κ opiates had DSR values between 0.3 and 2.2, regardless of their nature as agonists or antagonists. In contrast, the DSR for μ opiates ranged from 3.4 to 11. In rat brain membranes, UM 1382 (U-50, 488, a compound with pronounced κ activity) exhibited a DSR of 0.3, while the corresponding value for morphine was 7.4. Dynorphin-(1-13) had a DSR of 1. Within each of the two groups, the simple sodium ratio continued to serve as an index for the agonist or antagonist property of the tested opiates.
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U2 - 10.1016/0024-3205(84)90311-4
DO - 10.1016/0024-3205(84)90311-4
M3 - Article
C2 - 6145076
AN - SCOPUS:0021368032
VL - 34
SP - 2129
EP - 2138
JO - Life Sciences
JF - Life Sciences
SN - 0024-3205
IS - 22
ER -