Binding of [3H]-dopamine to human lymphocytes: possible relationship to neurotransmitter uptake sites.
Freshly isolated human lymphocytes from 11 healthy subjects had specific binding sites for dopamine which were dependent on time, temperature and sodium, and appeared to follow Michaelis-Menten kinetics. The apparent affinity constant (KD) of human lymphocytes for dopamine and the maximal number of binding sites (Bmax) were 109 +/- 21 nM and 2.66 +/- 1.75 pmol/10(7) cells, respectively. Dopamine binding was markedly affected by cocaine (IC50 = 150 nM) and other inhibitors of biogenic amine uptake. The relatively high potency of cocaine in competing for dopamine binding suggested that human lymphocytes may serve as a readily accessible model to detect changes in the neuronal uptake of dopamine and perhaps other monoamine neurotransmitters.
Department of Radiology (Division of Nuclear Medicine), Emory University School of Medicine, Atlanta, GA.
B A
BA
Faraj
Z L
ZL
Olkowski
R T
RT
Jackson
D000328:Adult; D003042:Cocaine / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D007700:Kinetics; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018377:Neurotransmitter Agents / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism
D007202:Indicators and Reagents; D018377:Neurotransmitter Agents; D017981:Receptors, Neurotransmitter; D012964:Sodium; D003042:Cocaine; D011188:Potassium; D004298:Dopamine