Km. Naseem et Kr. Bruckdorfer, HYDROGEN-PEROXIDE AT LOW CONCENTRATIONS STRONGLY ENHANCES THE INHIBITORY EFFECT OF NITRIC-OXIDE ON PLATELETS, Biochemical journal, 310, 1995, pp. 149-153
Simultaneous application of NO and H2O2 to human platelets at physiolo
gically relevant concentrations increased inhibition of platelet aggre
gation by NO almost 100-fold. If NO and H2O2 were mixed before the add
ition to platelets, the inhibitory effect remained but still depended
on the presence of NO. This suggested an enhanced sensitivity of the p
latelets to residual NO in the presence of H2O2. The inhibition by the
NO/H2O2 mixture was not due to peroxynitrite and was only partly reve
rsed by radical scavengers. The mechanism includes enhanced formation
of cyclic GMP in response to NO in the presence of H2O2. H2O2 may play
a positive physiological role by amplification and/or prolongation of
the action of NO.