Altered platelet alpha2-adrenoceptors in patients with angina pectoris

摘要: The alpha2-adrenoceptor located on noradrenergic neurons regulates the release of norepinephrine by negative feedback. This receptor is also human blood platelets, and number these receptors correlated with plasma content. purpose this study was to determine status platelet alpha2-adrenoceptors in patients symptomatic asymptomatic coronary artery disease. It hypothesized that disease might have a decrease be related increased neuronal release. Specific, high-affinity binding alpha2-agonist, 3H-clonidine, alpha2-antagonist, 3H-yohimbine, isolated membranes used maximal sites (in fmol/mg protein ± standard error mean) dissociation constant nM) alpha2-receptors. In normal subjects, for 3H-clonidine 32 2 5.5 0.6 (n = 26); 3H-yohimbine 165 ±12 4.0 0.5 16). disease, there 38% (number 20 3; 6.6 1.2; n 9; p affinity constants concentrations did not differ among three groups. If similar changes occur nerve terminals, may represent primary abnormality permits enhanced or secondary down regulation response synaptic levels norepinephrine.