GTP gamma S and forskolin-stimulated adenylyl cyclase activity in post-mortem brain from depressed suicides and controls.

We have measured basal, guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) and forskolin-stimulated adenylyl cyclase activity in samples of frontal and parietal cortex obtained at post-mortem from suicides, with a firm retrospective diagnosis of depression. The suicides were divided into those free of antidepressants and those receiving antidepressants. Each suicide was individually compared to a gender and age-matched control. Although we found no significant differences in adenylyl cyclase activity between controls and either antidepressant-free or antidepressant-treated suicides, there was a trend for lower stimulated adenylyl cyclase activity in suicides.