Autoradiographic evidence for passage of vincamine through the blood-brain barrier.

Autoradiographies of the brain and of the cerebellum were performed in 8-month old rats intraperitoneal injection of 3H-labelled vincamine. Only those samples that were processed by freeze-drying or by freeze-substitution gave interpretable results. Some specifically labeled cells were found in the molecular layer of the cerebellar cortex as well as in the internal granular and in the deeper layers of the cerebral cortex. They did not belong to the vascular system. It was concluded that vincamine or its metabolites crosses the blood-brain barrier. Any attempt to explain a possible action of the substance on the brain function should thus also consider the cellular components of the central nervous system and not only the haemodynamics of the cerebral circulation.