ABSTRACT
Inhibitors of signaling enzymes such as guanosine-5;-O-2-thiodiphosphate, aristolochic acid, aspirin, indomethacin, and trifluoperazine block H2O2-induced platelet aggregation and H2O2-induced increase in the intracellular concentration of Ca2+. These findings suggest that the effect of H2O2 on platelets is associated with activation of signal pathways responsible for increase in the concentration of intracellular Ca2+. On H2O2-induced platelet aggregation, the concentration of cAMP in the cytoplasm decreases and that of cGMP increases.
Subject(s)
Calcium/antagonists & inhibitors , Cyclic AMP/metabolism , Cyclic GMP/metabolism , Hydrogen Peroxide/pharmacology , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation/drug effects , Adenosine Diphosphate/metabolism , Adenosine Diphosphate/pharmacology , Arachidonic Acid/metabolism , Arachidonic Acid/pharmacology , Blood Platelets/drug effects , Blood Platelets/metabolism , Calcium/metabolism , Calcium Signaling/drug effects , Cyclic AMP/analysis , Cyclic GMP/analysis , Humans , Hydrogen Peroxide/metabolism , Platelet Aggregation Inhibitors/metabolismABSTRACT
Rabbit antibodies to 2',5'-linked triadenylate were prepared by immunization with (2',5')A3 conjugated via the 2'3'-levulinic group, (2'5')A3-Lev, to BSA. New radioimmunoassay for (2',5')oligoadenylates was developed using 125I thyrosine labeled derivative of (2',5')A3-Lev. Reactivity of antibodies with phosphorothioate and seco analogs of oligoadenylates was studied. It was found that (i) stereospecific substitution of the diastereotopic oxygens with sulfur in the internucleotide phosphodiester linkages changes the immunoreactivity of such analogs; (ii) the seco analogs of oligoadenylates display in some cases a rather high reactivity.
