Aim of the study was to assess whether platelet hyperaggregation to epinephrine, frequently observed in hypercholesterolemia is associated with an increase of α 2-adrenoceptor density and/or affinity for epimephrine. Thus, platelet aggregation and binding studies, using [ 3H]yohimbine as ligand, were performed on platelets isolated from 30 type IIa hypercholesterolemic patients (HC) and 23 controls. Platelet aggregation to epinephrine, evaluated as AC 50, was significantly higher in HC than in controls (0.9±1 vs 0.4±0.3 μg/ml p2-adrenoceptor density (Bmax) was observed in a subgroup of 13 HC patients, compared to 13 sex and age matched controls (280±61 and 230±49 fmol/mg prot., respectively, p2-receptor density is increased in hypercholesterolemia and that plasma and LDL-cholesterol levels significantly correlate with platelet α 2-receptor density. These findings explain, at least in part, the enhanced platelet response to epinephrine observed in hypercholesterolemia.
|Number of pages||1|
|Journal||Clinical Pharmacology and Therapeutics|
|Publication status||Published - 1997|
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