Increased platelet sensitivity and thromboxane B2 formation in type-II hyperlipoproteinaemic patients.
Platelet aggregation induced by collagen, ADP and epinephrine, was monitored in 150 type-II patients (115 type IIA and 35 type IIB) and compared with a reference group of normolipidaemic controls; in addition, malondialydehyde formation and thromboxane B2 were examined in a subsample of the type-IIA patients. Threshold aggregatory concentrations were significantly lower in the whole group of type-II patients for all three aggregating agents; no difference in terms of aggregatory response was detected between platelets from type-IIA and -IIB patients. Only 56% of type-II patients, however, exceeded the 95th percentile of the threshold aggregatory concentrations in controls. The formation of malondialdehyde in platelet-rich plasma stimulated with thrombin and collagen, was significantly higher in platelets from type-IIA patients. The production of thromboxane B2 by platelets, from endogenous arachidonic acid in type-IIA patients, was significantly higher and exceeded the highest level found in controls.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001095:Arachidonic Acids / Q000097:blood; D001792:Blood Platelets / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D003094:Collagen / Q000494:pharmacology; D005260:Female; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000097:blood*; D066298:In Vitro Techniques; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D010974:Platelet Aggregation; D013929:Thromboxane B2 / Q000097:blood*; D013931:Thromboxanes / Q000097:blood*
D001095:Arachidonic Acids; D013931:Thromboxanes; D008315:Malondialdehyde; D013929:Thromboxane B2; D003094:Collagen; D002784:Cholesterol