Choline fluxes to and from the rat cerebral cortex studied with the 'cup techniques' in vivo

In order to investigate the vessel integrity and the permeability for plasma Ch in control conditions and during local treatments on male Wistar rats carboxyl-C 14-inulin ((14C)-inulin methyl-tritium-Ch chloride were infused in the tail vein. At the end of the infusion, blood samples were taken from the heart and radioactivity was measured after extraction. In the plasma, radioactivity was totally water-soluble, indicating that it represented the free Ch pool. When the removal mechanisms were investigated trace amounts of tritium-Ch were added to the Ringer solution. Ch was determined by two different methods: the chemiluminescence method and the adioenzymatic method