Biosynthesis of catecholamines, uptake of 3H-noradrenaline, and reactivity of cardiovascular system of the rat after chronic and acute treatment with a new antidepressant agent, IPF C-45.

The effect of acute and chronic treatment of rats with IPF C-45 on the following biochemical and pharmacological parameters was tested: catecholamine concentration in brain, heart and adrenals, 3H-noradrenaline uptake by cardiac muscle, the action on catecholamine synthesis following treatment with alpha-methyl-p-tyrosine, reactivity of cardiovascular system to catecholamines and isoproterenol-induced tachycardia. Given chronically, IPF C-45 does not affect noradrenaline uptake by the cardiac muscle. Both chronic and acute administration of the drug decelerates catecholamine biosynthesis by inhibition of tyrosine hydroxylase activity. It seems that the action of IPF C-45, a benzonaphthyridone derivative, affects catecholamine metabolism in a manner distinctly different from that of tricyclic antidepressant drugs.