Activation of Brain Succinate Dehydrogenase by Lithium

IN spite of the widespread use of lithium salts as therapeutic and prophylactic agents against manic-depressive psychosis^{1, 2}, little is known about the mechanism of lithium effects^{3, 4}. Li⁺ stimulates noradrenergic neurones³, increases the uptake of this amine by isolated rat brain synaptosomes^{5, 6}, increases serotonin uptake into platelets obtained from manic-depressive patients⁷ and increases the levels of serotonin and tryptophan in rat brain⁸. On the other hand, Lallier observed inhibitory action of LiCl on dehydrogenase activity in homogenates of Rana fusca⁹. We have investigated whether long term treatment with Li⁺ affects brain succinate dehydrogenase activity.