EFFECT OF LITHIUM ON DOPAMINE UPTAKE BY BRAIN SYNAPTOSOMES

Abstract
LiCl exerted 2 opposite effects on dopamine uptake by synaptosomes isolated from rat caudate nucleus. Added in vitro, it inhibited dopamine uptake; whereas administered chronically in vivo, it enhanced dopamine uptake in vitro. Thus, in vitro, 1, 2.5, 5 and 10 meq/l of LiCl decreased 3H dopamine uptake by 13, 17, 25 and 31%, respectively. Synaptosomes isolated from rats treated with LiCl for 20 days, showed a 23% increase in 3H dopamine uptake with respect to synaptosomes isolated from control rats. Chronic Li treatment probably stimulated a compensatory mechanism which overcame its direct inhibitory effect on 3H dopamine uptake.
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