Abstract: | Subcutaneous injections of para-chloro-D, L-phenylalanine (pCl-Phe) and phenylalanine (Phe) over the last third of pregnancy were found to produce hyperphenylalaninemic states in maternal and fetal rats. The pCl-Phe, when administered to maternal animals alone or in conjunction with Phe, was associated with maternal muricide. The muricide was counteracted by the administration of 5-hydroxy-D, L-tryptophan prior to delivery. Prolonged treatment of maternal animals with pCl-Phe and Phe suppressed normal weight gain and resulted in smaller offspring. The elevated levels of maternal plasma Phe decreased with time, reflecting a lessening of pCl-Phe inhibition of maternal phenylalanine hydroxylase and normal Phe clearance. Fetal plasma Phe levels mirrored those of treated maternal animals. Similarly, fetal brain Phe reflected the increase in fetal plasma Phe. |