The uptake of DH-ergotoxine by different parts of the cat brain.

The distribution pattern of 3H-DH-ergotoxine, labelled by a direct hydration with tritium, was investigated in the cat brain. Apart from the pituitary gland, the brain shows an average DH-ergotoxine concentration of 10(-7) M. A 15% greater incorporation of DH-ergotoxine occurs in the cerebellum than in the cerebrum. In gradient centrifugation studies it is seen that 60% of the incorporated DH-ergotoxine is localized in the synaptosomal fraction. This finding seems to verify the microhistautoradiographic results of this investigation. The observation of a DH-ergotoxine binding in selected structures of the CNS , predominantly the synapses, could explain central nervous activities of DH-ergotoxine.