[Blood-brain barrier. II. Kinetics of distribution of 3H-parahydroxyamphetamine in brain structures after intravenous administration in the rat].

Intravenously injected parahydroxyamphetamine hardly penetrates into the Central Nervous System, since, 5 minutes after injection, the tissue to plamsa concentration ratio for brain and cerebrospinal fluid amounts to 0,67 and 0,35 respectively. Its concentration in muscle is 5 times higher than in plasma. In the brain, the molecule is preferentialy taken up by the corpus striatum and the hypothalamus. Thus, parahydroxylation of amphetamine inhibits the penetration of the molecule into the brain and suppresses its cortical fixation. These characteristics could explain why this parahydroxylated amine has no psychotropic action.