TY - JOUR
T1 - Nitric oxide-mediated cyclooxygenase activation. A key event in the antiplatelet effects of nitrovasodilators
AU - Salvemini, D.
AU - Currie, M. G.
AU - Mollace, V.
PY - 1996
Y1 - 1996
N2 - We have evaluated the contributions of nitric oxide (NO) and prostacyclin (PGI2) in the in vivo antiplatelet effects of clinically useful nitrovasodilators. In rats, intravenous infusion of three NO donors, glyceryl trinitrate, sodium nitroprusside, or 3'-morpholinosydnonimine, the stable metabolite of molsidomine, released 6-keto PGF1α (the stable metabolite of PGI2) and inhibited ex vivo human platelet aggregation to adenosine diphosphate by at least 80%. In in vitro studies, glyceryl trinitrate, sodium nitroprusside, and 3'-morpholinosydnonimine, at clinically attainable concentrations, increased cyclooxygenase activity in endothelial cells (EC), which resulted in a four- to sixfold release of 6-keto PGF1α. Pretreatment of the EC with hemoglobin which binds to and inactivates the biological actions of NO, but not by methylene blue (MeB), attenuated the NO-mediated PGI2 from the EC by at least 70%. Release of 6-keto PGFIα by the NO donors increased the ability of these compounds to inhibit thrombin-induced human platelet aggregation by at least 10 times; this potentiation was inhibited by hemoglobin but not by MeB. MeB blocked the direct anti-platelet effect of the NO donors in the absence of EC, in summary, we have demonstrated that NO, directly as well as together with an NO-driven cyclooxygenase activation (and hence PGI2), release contributes to the marked anti-platelet effects observed after the in vivo administration of clinically used nitrovasodilators.
AB - We have evaluated the contributions of nitric oxide (NO) and prostacyclin (PGI2) in the in vivo antiplatelet effects of clinically useful nitrovasodilators. In rats, intravenous infusion of three NO donors, glyceryl trinitrate, sodium nitroprusside, or 3'-morpholinosydnonimine, the stable metabolite of molsidomine, released 6-keto PGF1α (the stable metabolite of PGI2) and inhibited ex vivo human platelet aggregation to adenosine diphosphate by at least 80%. In in vitro studies, glyceryl trinitrate, sodium nitroprusside, and 3'-morpholinosydnonimine, at clinically attainable concentrations, increased cyclooxygenase activity in endothelial cells (EC), which resulted in a four- to sixfold release of 6-keto PGF1α. Pretreatment of the EC with hemoglobin which binds to and inactivates the biological actions of NO, but not by methylene blue (MeB), attenuated the NO-mediated PGI2 from the EC by at least 70%. Release of 6-keto PGFIα by the NO donors increased the ability of these compounds to inhibit thrombin-induced human platelet aggregation by at least 10 times; this potentiation was inhibited by hemoglobin but not by MeB. MeB blocked the direct anti-platelet effect of the NO donors in the absence of EC, in summary, we have demonstrated that NO, directly as well as together with an NO-driven cyclooxygenase activation (and hence PGI2), release contributes to the marked anti-platelet effects observed after the in vivo administration of clinically used nitrovasodilators.
KW - cyclooxygenase
KW - nitric oxide
KW - platelet aggregation
KW - prostacyclin
UR - http://www.scopus.com/inward/record.url?scp=0029894331&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029894331&partnerID=8YFLogxK
M3 - Article
C2 - 8647949
AN - SCOPUS:0029894331
VL - 97
SP - 2562
EP - 2568
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
SN - 0021-9738
IS - 11
ER -