Brain alpha-adrenoceptors in depressed suicides

alpha(1)-Adrenoceptors and alpha(2)-adrenoceptors were measured by radioligand binding to homogenates of brain samples obtained at post-mortem from suicides with a retrospective diagnosis of depression, and age and gender-matched controls. Suicides were subdivided into those who had been free of antidepressant drugs for at least three months, and those in whom prescription of antidepressant drugs was clearly documented. The number of alpha(1)-adrenoceptors (or alpha(1A) + alpha(1D)-adrenoceptors) did not differ significantly between antidepresant-free or antidepressant-treated suicides and controls. In antidepressant-free suicides, the number of alpha(2)-adrenoceptors was significantly higher in temporal cortex (Ba 21/22). alpha(2A)-Adrenoceptors did not differ significantly from controls in this brain region, suggesting the involvement of other alpha(2)-adrenoceptor subtypes. In antidepressant-treated suicides, significantly lower numbers of alpha(2)-adrenoceptors were found in occipital cortex and hippocampus (and for alpha(2A)-adrenoceptors in caudate and amygdala) compared to controls. (C) 1997 Elsevier Science B.V.