Regionally specific age-dependent decline in alpha 2-adrenoceptors: an autoradiographic study in human brain.
The effect of sex, postmortem delay and aging on alpha 2-adrenoceptor binding was studied in tissue sections from several representative regions of the human brain from 21 subjects using [3H]UK-14304 as a ligand. Sex and postmortem delay did not influence the density of alpha 2-receptors. Aging resulted in clear decreases in most forebrain areas examined (n. basalis greater than basal ganglia greater than hypothalamus greater than fronto-temporal cortex greater than hippocampus greater than visual cortex), whereas alpha 2-receptors did not significantly change with age in the amygdala and several infratentorial areas. We conclude that age-related, regionally specific decreases in the density of alpha 2-receptors occur in the human brain. The implications of these findings for age-dependent noradrenergic degeneration are discussed.
Department of Physiology and Pharmacology, University Hospital Marqués de Valdecilla, University of Cantabria, Santander (Spain).
J
J
Pascual
C
C
del Arco
A M
AM
González
A
A
Díaz
E
E
del Olmo
A
A
Pazos
D000316:Adrenergic alpha-Agonists / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001345:Autoradiography; D001921:Brain / Q000254:growth & development* / Q000378:metabolism / Q000473:pathology; D000068438:Brimonidine Tartrate; D003000:Clonidine / Q000031:analogs & derivatives* / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D009928:Organ Specificity; D011180:Postmortem Changes; D011810:Quinoxalines / Q000378:metabolism*; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D014316:Tritium
D000316:Adrenergic alpha-Agonists; D011810:Quinoxalines; D011942:Receptors, Adrenergic, alpha; D014316:Tritium; D000068438:Brimonidine Tartrate; C016986:apraclonidine; D003000:Clonidine