A Mehanism of the Indole Defect in Experimental Phenylketonuria

Science  24 Aug 1962:
Vol. 137, Issue 3530, pp. 604-605
DOI: 10.1126/science.137.3530.604


Rats made phenylketonuric by a diet containing high levels of either phenylalanine alone, or phenylalanine and tyrosine, show a marked reduction in total cerebral stores of serotonin. Evidence from studies both in vitro and in vivo indicates that an important mechanism of this impairment in the metabolism of serotonin is the inhibition by high levels of these amino acids of the active transport of the precursor of serotonin, 5-hydroxytryptophan, into brain.