Sodium-sensitive cocaine binding to rat striatal membrane: possible relationship to dopamine uptake sites.
In rat striatal membranes, NaCl induced a twofold increase in the maximal number of cocaine binding sites but did not alter the affinity of these sites for cocaine. This effect was concentration-dependent, specific to sodium ions, and occurred in membranes prepared from corpus striatum but not from other brain regions. Lesions with 6-hydroxydopamine but not with kainic acid eliminated the sodium-induced increase in binding and produced a decrease in the Bmax of binding measured in the presence of NaCl. The capacity of a series of drugs to interfere with Na+-dependent cocaine binding correlated well with their capacity to inhibit [3H]dopamine uptake into rat striatal synaptosomes. The present results suggest that Na+-dependent cocaine binding sites are localized presynaptically on dopaminergic nerve terminals in corpus striatum, and may be related to dopamine uptake sites.
D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D003042:Cocaine / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000378:metabolism*; D012492:Salts; D012964:Sodium / Q000494:pharmacology*; D013574:Synaptosomes / Q000378:metabolism
D011954:Receptors, Dopamine; D012492:Salts; D012964:Sodium; D003042:Cocaine; D004298:Dopamine