[The effects of different amino acids and structural analogues on the penetration of L-tryptophan in mouse brain in vivo and in vitro]. 
Various amino-acids and substituted tryptophane derivatives inhibit the penetration of tryptophane in mice brain slices.  Their inhibitory effect is rapidly neutralized in vivo by a perpheral mechanism, including the binding of tryptophane to circulating serumalbumins.