Decreased density and sensitivity of alpha 2-adrenoceptors in the brain of spontaneously hypertensive rats.
The specific binding of the agonist [corrected], [3H]clonidine, to neural membranes and clonidine-induced mydriasis were used to evaluate the density and sensitivity [corrected] of alpha 2-adrenoceptors in the brain of spontaneously hypertensive rats (SHR) and sex- and age-matched normotensive Wistar-Kyoto (WKY) rats. In hypertensive rats (SHR) the density of alpha 2-adrenoceptors was reduced in the cerebral cortex, hypothalamus and medulla oblongata (20-27%), as was the dose-pupillary response curve for clonidine (1.8-fold). The results demonstrated that this model of genetic hypertension is associated with desensitization of alpha 2-adrenoceptors in the brain.
Olmos
G
G
Department of Fundamental Biology and Health Sciences, University of the Balearic Islands, Palma de Mallorca, Spain.
Miralles
A
A
Barturen
F
F
García-Sevilla
J A
JA
D000818:Animals; D001921:Brain / Q000378:metabolism*; D003000:Clonidine / Q000378:metabolism; D006973:Hypertension / Q000235:genetics / Q000378:metabolism*; D008297:Male; D015878:Mydriasis / Q000139:chemically induced; D011680:Pupil / Q000187:drug effects; D011869:Radioligand Assay; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*
D011942:Receptors, Adrenergic, alpha; D003000:Clonidine