[Blood platelet alpha adrenergic receptors in congestive heart failure. Effects of ACE inhibition]. / I recettori alfa adrenergici piastrinici nello scompenso cardiaco congestizio. Effetti dell'ACE-inibizione.

ABSTRACT

Platelet alpha-2-adrenergic receptor number and affinity were examined in 12 patients with class IV NYHA congestive heart failure (CHF) and 10 normal volunteers paired for age and sex. Platelet alpha-2-adrenergic receptor number is significantly decreased in CHF patients (178 +/- 18 fmol/mg prot. vs 282 +/- 21 fmol/mg prot. p less than 0.05). After Captopril treatment (6 weeks) alpha-2-receptor number increased but this increase was not statistically significant (236 +/- 28 fmol/mg prot.). This study supports the hypothesis that increased levels of circulating catecholamines in CHF lead to a decrease in platelet alpha-2-adrenoreceptors. Improved cardiac function following administration of Captopril could lead to a withdrawal of sympathetic tone. Captopril may also interact with sympathetic nervous function.