Cardiovascular Regulation in Mice Lacking α 2 -Adrenergic Receptor Subtypes b and c

Abstract

α₂-Adrenergic receptors (α₂ARs) are essential components of the neural circuitry regulating cardiovascular function. The role of specific α₂AR subtypes (α_2a, α_2b, and α_2c) was characterized with hemodynamic measurements obtained from strains of genetically engineered mice deficient in either α_2b or α_2c receptors. Stimulation of α_2b receptors in vascular smooth muscle produced hypertension and counteracted the clinically beneficial hypotensive effect of stimulating α_2a receptors in the central nervous system. There were no hemodynamic effects produced by disruption of the α_2c subtype. These results provide evidence for the clinical efficacy of more subtype-selective α₂AR drugs.