Effect of taurine on platelet release reaction and platelet ATP metabolism

Abstract

The purpose of the present study is to clarify the effect of taurine on platelet release reaction and platelet ATP metabolism in 13 patients with ischemic heart disease and 10 patients with cerebral infarction.
In vitro, amounts of ATP in platelet rich plasma (PRP-ATP) and platelet ATP (PLT-ATP) were measured by a luciferin-luciferase method before and after the incubation with or without 10mM taurine and also after the stimulation by 4.6μM ADP. In the study using taurine, PRP-ATP was not significantly changed and PLT-ATP was significantly decreased by the addition of 4.6μM ADP. On the other hand, in the control study, PRP-ATP was significantly increased and PLT-ATP was significantly decreased by the addition of 4.6μM ADP. Before and after oral administration of taurine 6g/day for 4 weeks, platelet aggregation was measured by Born's method and plasma β-thromboglobulin (β-TG) and platelet factor 4 (PF4) were measured by the radioimmunoassay. The platelet secondary aggregation induced by 4.6μM ADP, and plasma PF4 were significantly decreased after taurine treatment.
The present results indicate that the effects of taurine on platelet function may be the primary inhibition of release reaction and that taurine may inhibit secondly platelet aggregation. It remains to be investigated wether the inhibition of taurine to platelet release reaction is due to ATP-dependent mechanism or ATP-independent one.