Inhibition by Phenylalanine of the Entry of 5-Hydroxy-Tryptophan-l-G14 into Cerebrospinal Fluid.

Abstract
Summary High plasma levels of L-phenyl-alanine inhibit the entry of 5-hydroxytrypto-phan-C14 into the CSF of dogs. CSF is an accessible body fluid that may be used to study transport of amino acids into the CNS.