Effects of methylglyoxal on platelet hydrogen peroxide accumulation, aggregation and release reaction.
Methylglyoxal generates a slight increase in the basal level of hydrogen peroxide in platelets. The oxidation effect of methylglyoxal significantly potentiated by thrombin, depends on both the ketoaldehyde and the agonist concentrations. A further significant increase in hydrogen peroxide accumulation was obtained in platelets pretreated with the alkylating agent N-ethylmaleimide which depletes GSH and blocks glutathione peroxidase. Resting platelets completely transform the ketoaldehyde into D(-)lactate, whereas stimulated platelets transform about 10-15 per cent of the metabolized methylglyoxal into D(-)lactate. The metabolic modifications generated by methylglyoxal such as the GSH depletion and hydrogen peroxide accumulation induce modifications in platelet function. Methylglyoxal inhibits platelet aggregation induced by several agonists and ATP release induced by thrombin.
Leoncini
G
G
Istituto Policattedra di Chimica Biologica, Università di Genova, Italy.
Poggi
M
M
D001792:Blood Platelets / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007773:Lactates / Q000378:metabolism; D015539:Platelet Activation / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology / Q000633:toxicity; D011765:Pyruvaldehyde / Q000494:pharmacology* / Q000633:toxicity; D013917:Thrombin / Q000494:pharmacology
D004791:Enzyme Inhibitors; D007773:Lactates; D010975:Platelet Aggregation Inhibitors; D011765:Pyruvaldehyde; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D013917:Thrombin; D005033:Ethylmaleimide