The Effects of Long-Term Treatment with Lithium on Adenylate Cyclase Coupled with Catecholamine Receptors

Increment of cyclic AMP in tissue slices in response to noradrenaline and dopamine stimulation was studied in all part of the rat brain. Chronic lithium administration significantly inhibited the sensitivity of noradrenaline-sensitive adenylate cyclase in the frontal cortex, whereas the sensitivity of dopamine-sensitive adenylate cyclase was significantly inhibited in bulbus olfactorius and hippocampus. A possible relationship between the antidepressant action of lithium and its significant inhibition of the sensitivity of noradrenaline-sensitive adenylate cyclase was therefore suggested. The anti-manic effect, on the other hand, may be related to the inhibitory action on the sensitivity of dopamine-sensitive adenylate cyclase