Antiaggregant Effect of Taurine Chloramines in the Presence of Serum Albumin

The effects of taurine chloramine derivatives on initial aggregation of isolated platelets suspended in buffered saline were studied. Inhibition of ADP-induced aggregation in pure cell suspension depended on the structure of chloramine antiaggregants. The most effective of them was N,N-dichlorotaurine; its concentration needed for 50% inhibition of aggregation was about 0.1 mM. Weaker antiaggregants N-chloro-N-methyltaurine and N-chlorotaurine in a final concentration of 0.5 mM reduced platelet aggregation by only 10%. The studied chloramines considerably differed by their characteristics (velocity of the reaction with sulfur-containing groups of atoms). N,N-dichlorotaurine exhibited the weakest reactivity with methionine thioester group. In turn, the velocity constant with reduced glutathione was by 2-3 orders of magnitude higher than that of other chloramines. Antiaggregant effect of taurine chloramine derivatives was 2-fold higher in the presence of serum albumin, presumably due to special interactions of taurine chloramines in complex with albumin with platelets.