Interaction between cholinotropic and adrenotropic drugs on the histofluorescence of the central catecholamine structures in the rat.

Male Wistar rats were given phentolamine or phenoxybenzamine in the lateral ventricles in doses of 1 mg/kg. After 30 minutes they received in the same way atropine in doses of 1 mg/kg or carbachol in doses of 0.05 mg/kg. The control group was given physiological saline. The animals were decapitated 30 minutes after drug administration. The Falck and Hillarp histofluorescence method was applied. The areas of DA (nigrostriatal and meso-limbic) and NA systems were examined. It was found, that atropine increased the intensity of fluorescence in comparison with the control group, in all areas of DA structures. The action of carbachol was more differentiated. In the substantia nigra (A8 and A9) respectively in the globus pallidus and the nucleus arcuatus (A12) its effect was the same as that of atropine. In other areas it caused weakening of fluorescence or showed no effect. In the NA system atropine weakened the fluorescence considerably while carbachol increased it in five out of eleven areas. The interaction of cholinotropic and adrenotropic drugs is disscused.