Involvement of mercury in platelet aggregation--probable mechanism of action

Both in vivo and in vitro Hg2+ caused dose dependent inhibition of rat platelet aggregation. However, as low a dose as 88.8 pM Hg2+ could initiate ADP-induced aggregation even in the absence of added calcium. The action of Hg2+ was found to be unaffected by antagonists such as cAMP and theophylline either alone or in combination. Hg2+ induced platelet aggregation was inhibited completely by pre-incubation with aspirin (1 mmol.L-1), but it was ineffective when added after Hg2+. The results also indicate that the normal platelet function is affected by both high and low concentrations of Hg2+.