Rilmenidine selectivity for imidazoline receptors in human brain.
The selectivity of three centrally acting antihypertensive agents for the medullary imidazoline-preferring receptors (IPR) versus cortical alpha-adrenoceptors was investigated in human brain. [3H]Clonidine binding was studied in various membrane preparations. Competition experiments were performed. Cortical membrane preparations were used as they mainly contained classical alpha-adrenoceptors whereas medullary membrane preparations from the nucleus reticularis lateralis contained only IPR insensitive to catecholamines. Rilmenidine, a new antihypertensive agent, appeared 2.5 and 3.5 times more selective than clonidine and guanfacine, respectively, for medullary IPR sites than for cortical alpha-adrenoceptors, thus providing a possible explanation for the low sedative effects of this new molecule.
Bricca
G
G
Laboratoire de Pharmacologie Cardiovasculaire et Rénale, CNRS URA 589, Faculté de Médecine, Université Louis Pasteur, Strasbourg, France.
Dontenwill
M
M
Molines
A
A
Feldman
J
J
Tibirica
E
E
Belcourt
A
A
Bousquet
P
P
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D054755:Imidazoline Receptors; D066298:In Vitro Techniques; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010080:Oxazoles / Q000494:pharmacology*; D011955:Receptors, Drug / Q000187:drug effects* / Q000378:metabolism; D000077769:Rilmenidine
D000316:Adrenergic alpha-Agonists; D054755:Imidazoline Receptors; D009419:Nerve Tissue Proteins; D010080:Oxazoles; D011955:Receptors, Drug; D000077769:Rilmenidine