Role of alpha2-adrenergic receptors in hypertension.
This is a brief review of a series of experiments conducted over the past two decades, exploring the role of the alpha2-adrenergic receptors (alpha2-AR) in salt-induced hypertension. The data suggest that salt loading alters the activity of central alpha2-AR, resulting in a hypertensive hyperadrenergic state. Studies to separate the role of each alpha2-AR subtype (alpha2A, alpha2B, and alpha2C) have used genetically engineered mice with disrupted genes for each subtype, or gene treatment in rats with antisense-oligodeoxynucleotides targeting a specific gene sequence. Taken together, the results of these studies indicate that the alpha2A-AR is centrally predominant and exerts a tonic sympathoinhibitory function, whereas peripherally it has a vasoconstrictive effect; the alpha2B-AR is responsible for the central hypertensive sympathoexcitatory response to salt, but is not expressed on vascular wall structures; and the alpha2C-AR seems to have no hemodynamic function.
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Department of Medicine, Boston University School of Medicine, Massachusetts 02118, USA. hgavras@bu.edu
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D000818:Animals; D016375:Antisense Elements (Genetics); D005818:Genetic Engineering; D006973:Hypertension / Q000503:physiopathology*; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D012016:Reference Values
D016375:Antisense Elements (Genetics); D011942:Receptors, Adrenergic, alpha