Inhibition by Phenylalanine of the Entry of 5-Hydroxy-Tryptophan-l-G 14 into Cerebrospinal Fluid. ∗

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.