Decreased dopamine uptake into platelet storage granules in Gilles de la Tourette disease

The movement disorder of Gilles de la Tourette (GdlT) disease may reflect hyperactivity of the basal ganglionic dopamine system. Since platelets have been suggested as peripheral models for the study of catecholamine neurons, we developed a method to measure the uptake of [3H]-DA into platelet storage granules (PSG). In the present report, PSG were incubated with [3H] DA, and Vmax and Km values were calculated by linear regression analysis (Lineweaver Burke plot). The uptake of DA (0.5-5 microM) by PSG from 18 GdlT patients was significantly lower (p < .0001) compared to 15 controls (Vmax mean +/- SD, 107.5 +/- 42.5 and 265.3 +/- 66.5 fmole/mg protein resp.). The decrease of DA uptake in GdlT may reflect compensatory presynaptic changes that reduce DA activity.