[Platelet aggregation in whole blood and thromboxane B2 in type II and IV hyperlipidemia].

Platelets play an essential role in the pathogenesis of atherosclerosis; by impedance method we valued in whole blood platelet aggregation induced by collagen in 40 healthy subjects and in 40 type II and type IV hyperlipemic subjects. Meanwhile by radioimmunoassay we dosed thromboxane B2, a stable product of thromboxane A2, released by platelets during activation, in 7 healthy subjects and 25 hyperlipemic subjects. The statistical investigation put in evidence that at higher plasmatic levels of cholesterol, triglycerides and LDL correspond a greater platelet sensitivity to the aggregating agent, while the opposite happens to higher levels of HDL. The dosage of thromboxane B2 put in evidence a moderate increase in hyperlipemic as to healthy subjects, probably pointing to a state of platelet activity.