Uptake of Taurine, GAB A, 5‐HT, and Dopamine by Blood Platelets in Progressive Myoclonus Epilepsy

Abstract

Uptakes of 4 neurotransmitters (taurine, GABA, 5-HT [hydroxytryptamine] and dopamine) by blood platelets from patients with degenerative-type progressive myoclonus epilepsy (PME) and from controls were studied using different incubation times and different concentrations. Only taurine uptakes differed significantly between patients and controls: patients'' uptakes were 70-80% of control values at 10, 30, 60 and 120 min of incubation time. Km values were approximately the same, but Vmax values in PME patients were lower, showing quantitative but not qualitative differences in taurine uptake by PME platelets. A defect or inhibitory mechanisms of some factor needed in transport or binding of taurine (but not of GABA, 5-HT and dopamine) evidently is present in PME.