Open AccessNeurons and Receptors in the Rostroventrolateral Medulla Mediating the Antihypertensive Actions of Drugs Acting at Imidazoline Receptors
Author(s) -
Donald J. Reis
Publication year - 1996
Publication title -
journal of cardiovascular pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.762
H-Index - 100
eISSN - 1533-4023
pISSN - 0160-2446
DOI - 10.1097/00005344-199627003-00003
Subject(s) - rilmenidine , moxonidine , imidazoline receptor , rostral ventrolateral medulla , clonidine , pharmacology , receptor , medulla , chemistry , sympatholytic , agonist , adrenergic receptor , endocrinology , medicine , medulla oblongata , blood pressure , central nervous system
A group of clinically useful antihypertensive agents, including clonidine, moxonidine, and rilmenidine, are all ligands at alpha(2)-adrenergic and imidazoline (I-) receptors, the latter principally of the I1-subclass. These agents all lower blood pressure by reducing the activity of tonically active sympathoexcitatory reticulospinal neurons of the C1 area of the rostroventrolateral medulla (RVL). They tonically excite preganglionic sympathetic neurons in the spinal cord by release of L-glutamate and mediate most reflexes influencing blood pressure. The RVL contains alpha(2)-adrenergic and I1-receptors, and there is evidence to suggest that both receptors may participate in the hypotensive actions of the drugs. However, because only activation of the alpha(2)-adrenergic receptors appears responsible for somnolence, the imidazoline-receptor agonists moxonidine and rilmenidine, both relatively selective for I-receptors, may have superior clinical utility in antihypertensive therapy, since they are sympatholytic and also suppress the generation of angiotensin II.