Effects of acute and subacute cocaine administration on the CNS dopaminergic system in Wistar-Kyoto and spontaneously hypertensive rats: III. Dopamine uptake

摘要

The characteristics of dopamine uptake after acute and subacute cocaine administration were determined in striata from WKY and SHR. In acutely-treated (40 mg/kg, s.c.) rats, significant increases in the Vmaxof dopamine uptake were observed 30 min after the cocaine injection in both strains, without changes in Kmvalues. The in vitro IC50for cocaine was significantly decreased at 30 min in WKY and at 2 h in SHR. However, the in vitro IC50for GBR-12909 was significantly increased at 30 min and at 2 h in both strains following cocaine administration. In both strains, the density (Bmax) of the 3HGBR-12935 binding site was significantly increased at 30 min and at 2 h with no charges in Kd. In subacutely-treated (20 mg/kg, twice daily for 3 or 7 days) rats, a significant increase in the Kmfor dopamine uptake was observed in 7 day treated SHR. The in vitro IC50for GBR-12909 was significantly increased in 3 day treated WKY. The results suggest that cocaine administration alters dopamine uptake and characteristics of dopamine uptake sites in the rat brain.