Alpha 2-adrenoceptors in the brain of suicide victims: increased receptor density associated with major depression.
To examine directly in the brain the status of the alpha 2-adrenoceptor in major depression, the specific binding of the agonists [3H]clonidine and [3H]UK 14304 was quantitated in various brain regions of suicide victims with a retrospective diagnosis of depression or other psychiatric disorders. In depressed suicides, the binding capacity of [3H]clonidine was found to be increased in the hypothalamus (Bmax 35%-55% greater), and to a lesser extent in the frontal cortex, as compared with that in matched controls, schizophrenic suicides, or suicides with various diagnosis. The binding capacity of [3H]UK 14304 also was found increased in the frontal cortex (Bmax 30% greater), and to a lesser extent in the hypothalamus, of depressed suicides. In other brain regions such as the amygdala, hippocampus, and cerebellum there also was a tendency for an increased receptor density associated with suicide. Moreover, in the frontal cortex of suicides, the potency of norepinephrine in displacing the binding of the antagonist [3H]idazoxan also was found increased (Ki decreased eight-fold). The results indicate that the density and affinity of alpha 2A-adrenoceptors in the high-affinity state are increased in the brain of depressed suicides.
Department of Neurosciences, University of the Basque Country Medical School, Leoia, Spain.
J J
JJ
Meana
F
F
Barturen
J A
JA
García-Sevilla
D000293:Adolescent; D000316:Adrenergic alpha-Agonists / Q000493:pharmacokinetics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001667:Binding, Competitive / Q000502:physiology; D001921:Brain / Q000473:pathology; D001931:Brain Mapping; D000068438:Brimonidine Tartrate; D003000:Clonidine / Q000493:pharmacokinetics; D003866:Depressive Disorder / Q000473:pathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011810:Quinoxalines / Q000493:pharmacokinetics; D011869:Radioligand Assay; D011941:Receptors, Adrenergic / Q000032:analysis*; D012559:Schizophrenia / Q000473:pathology; D012565:Schizophrenic Psychology; D013405:Suicide / Q000523:psychology; D014754:Violence
D000316:Adrenergic alpha-Agonists; D011810:Quinoxalines; D011941:Receptors, Adrenergic; D000068438:Brimonidine Tartrate; D003000:Clonidine