Autoradiographic demonstration of increased alpha 2-adrenoceptor agonist binding sites in the hippocampus and frontal cortex of depressed suicide victims.
To examine directly in the brain the status of alpha 2-adrenoceptors in major depression, the specific binding of the agonist [3H]UK 14304 was measured by quantitative receptor autoradiography in the hippocampus and frontal cortex of suicide victims (n = 17) with a retrospective diagnosis of depression (n = 7) or other psychiatric disorders (n = 10) as well as of matched control subjects (n = 9). In suicide victims, a significant increase in the number of alpha 2-adrenoceptors was found in the CA1 field (40%) and dentate gyrus (20%) of the hippocampus and in the external layers I (33%) and II (31%) of the frontal cortex, compared with that in matched controls. In depressed suicide victims, the increase in alpha 2-adrenoceptors in the CA1 field (57%) was significantly greater (24%, p < 0.05) than that observed in the group of suicide victims with other diagnoses (26%). In the same depressed suicide victims, the increase in cortical alpha 2-adrenoceptors was restricted to layer I (34%) and it was equivalent to that found in layer I (33%) of suicide victims with other diagnoses. The results indicate that suicide is associated with increases in the high-affinity state of brain alpha 2-adrenoceptors adrenoceptors and that there is a pronounced localized increase of this inhibitory receptor in the hippocampus of depressed suicide victims.
González
A M
AM
Department of Physiology and Pharmacology, University of Cantabria Medical School, Santander, Spain.
Pascual
J
J
Meana
J J
JJ
Barturen
F
F
del Arco
C
C
Pazos
A
A
García-Sevilla
J A
JA
D000316:Adrenergic alpha-Agonists / Q000378:metabolism* / Q000494:pharmacology; D000328:Adult; D001345:Autoradiography; D001665:Binding Sites; D001923:Brain Chemistry; D000068438:Brimonidine Tartrate; D002540:Cerebral Cortex / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D003863:Depression / Q000378:metabolism*; D005260:Female; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008875:Middle Aged; D011810:Quinoxalines / Q000378:metabolism / Q000494:pharmacology; D018341:Receptors, Adrenergic, alpha-2 / Q000032:analysis / Q000378:metabolism*; D013405:Suicide
D000316:Adrenergic alpha-Agonists; D011810:Quinoxalines; D018341:Receptors, Adrenergic, alpha-2; D000068438:Brimonidine Tartrate