A comparison of the acute and chronic effects of four antidepressant drugs on the turnover of serotonin, dopamine and noradrenaline in the rat brain

The acute effects of imipramine, Org GB 94 and iprindol and the chronic effects of imipramine, desipramine, iprindol and Org GB 94 were studied on the turnover of dopamine, noradrenaline and serotonin in the whole rat brain. The effects of these drugs on amine turnover was assessed from the incorporation of tritiated tyrosine and tryptophan into the amines. Following acute administration, imipramine significantly reduced the turnover of serotonin whereas Org GB 94 increased that of noradrenaline. After chronic administration, imipramine and desipramine reduced the turnover of serotonin and dopamine, iprindol had no significant effect on brain amine turnover whereas Org GB 94 increased the turnover of noradrenaline. The effect of Org GB 94 on noradrenaline turnover was more marked after intraperitoneal than after oral administration.