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Age and the Platelet Serotonin Vasoconstrictor Axis in Essential Hypertension

1988; Lippincott Williams & Wilkins; Volume: 11; Linguagem: Inglês

10.1097/00005344-198800111-00009

1533-4023

Ruth Amstein, Natália Feťkovská, Thomas F. Lüscher, Wolfgang Kiowski, Fritz R. Bühler,

Nitric Oxide and Endothelin Effects

This review addresses the question of whether platelet-derived serotonin locally released at the resistance vessel wall may contribute via selective 5-hydroxytryptamine (5-HT) receptors to vasoconstriction and whether this chain of events is enhanced with age and high blood pressure. In platelets from animals and humans, both age and hypertension are associated with greater shape change and aggregation responses, reduced serotonin uptake and content, and increased release. Removal of the endothelium, age, and high blood pressure enhance vasoconstrictor responses to serotonin. In the presence of endothelial damage and arteriosclerotic vascular disease, particularly with reduced blood flow in areas of stenosis, platelets may aggregate, resulting in high local 5-HT concentrations and 5-HT-induced vasoconstriction. Since alpha 1-adrenoceptor-mediated vasoconstriction is independent of age, the age-related antihypertensive efficacy of the 5-HT2-receptor antagonist ketanserin (with alpha 1-blocking property) helps to define pharmacologically 5-HT2-receptor-mediated platelet aggregatory and vasoconstrictor mechanisms. 5-HT2-receptor antagonists represent a new antihypertensive tool with the potential of reducing thromboembolic complications and vascular damage, particularly in older patients.