The effects of peroxynitrite on pig platelet lipid peroxidation and the secretory process induced by thrombin.
The effects of peroxynitrite on the blood platelet secretory process and lipid peroxidation, were investigated. Peroxynitrite (ONOO-) is a reactive oxidant produced by the reaction of NO with the superoxide radical, which can diffuse into the cell and change the cell function. This study showed that treatment of blood platelets with ONOO- (0.03-2 mM) caused a dose-dependent inhibition of adenine nucleotides release but had no effect on the thrombin-induced protein exocytosis. Incubation of platelets with ONOO- (60 min, 0.25-2 mM) induced platelet lipid peroxidation. In thrombin-activated platelets pretreated with ONOO- for approximately 10 s (zero time), the level of thiobarbituric acid reactive substances, such as malonyldialdehyde (MDA) was reduced. It is suggested that the reduced amount of MDA in thrombin-stimulated platelets caused by ONOO- was due to inhibition of cyclo-oxygenase via nitration of tyrosine residues.
Nowak
P
P
Department of General Biochemistry, University of Lódź, Poland.
Wachowicz
B
B
D000227:Adenine Nucleotides / Q000032:analysis / Q000378:metabolism; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015227:Lipid Peroxidation / Q000187:drug effects*; D030421:Peroxynitrous Acid / Q000494:pharmacology*; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D013552:Swine; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013917:Thrombin / Q000494:pharmacology*
D000227:Adenine Nucleotides; D016861:Cyclooxygenase Inhibitors; D011506:Proteins; D017392:Thiobarbituric Acid Reactive Substances; D030421:Peroxynitrous Acid; D013917:Thrombin