(+)-(4aR,10bR)-3,4,4a,10b-Tetrahydro-4-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-ol hydrochloride

(+)-PD 128907 significantly decreases dialysate DA levels in D₃ knock out mice. The IC₂₅ values are 61 nM and 1327 nM, respectively, for wild type and D₃knock out mice. The ratio of the IC₂₅ values shows that (+)-PD 128907 is 22 times more potent in decreasing dialysate DA levels in wild type as compared to mice lacking the D₃ receptor. The D3 agonist evokes a dose related decrease in dialysate DA in wild type mice. Post-hoc analysis shows that all doses tested (0.03, 0.1 and 0.3 mg/kg) significantly inhibit dialysate DA. The IC₂₅ values are 0.05 and 0.44 mg/kg for wild type and knock out mice, respectively, indicating that systemically administered (+)-PD 128907 is 9 times more potent in decreasing dialysate DA in the ventral striatum of wild type as compared to D₃ knock out mice. Doses of 1 mg/kg or higher of (+)-PD 128907 markedly inhibits dialysate DA in both wild type and D₃ knock out mice^[3].