INHIBITION OF PLATELET ACTIVITY BY S-NITROSOGLUTATHIONE DURING CORONARY ANGIOPLASTY

Platelet activation is associated with acute vessel occlusion and chro nic restenosis after percutaneous transluminal coronary angioplasty (P TCA), Organic nitrates, which act by releasing the vasodilator and ant i-platelet agent nitric oxide (NO), have a predominantly vasodilator a ction and cause hypotension at doses required to inhibit platelet acti vation. S-nitrosoglutathione (GSNO) is an NO donor with a preferential action on platelets. We investigated platelet activation in patients undergoing PTCA and the effect of GSNO. Blood was sampled from the cor onary sinus to measure platelet surface expression of P-selectin and g lycoprotein IIb/IIIa as indices of platelet activation. In 7 control p atients, PTCA caused a rise in platelet surface expression of P-select in and glycoprotein IIb/IIIa, which was maximal 5 minutes after PTCA, indicating increased platelet activation despite treatment with aspiri n, glyceryl trinitrate, and heparin. 6 patients received an intracoron ary infusion of GSNO, starting 10 min before PTCA. GSNO significantly inhibited the PTCA-induced increase in platelet surface expression of P-selectin and glycoprotein IIb/IIIa without altering blood pressure. These findings show that platelets are activated following PTCA and th at GSNO can prevent this activation.