Effect of Phenylalanine Deficient Diet on Bone Marrow and Ammo Acid Metabolism. ∗

Summary

Normal premature infants fed a diet deficient in phenylalanine developed changes in their bone marrow within 24 to 48 hours. These marrow changes consisted specifically in cytoplasmic vacuolization of ery-throid precursors. Vacuoles also occurred in the myeloid elements. The vacuoles of the red cell precursors were associated with marked depression of serum phenylalanine concentrations to levels of 4 and 6 micromoles per liter. These effects were reversible within 48 hours by the addition of 100 mg per kg of phenylalanine to the diet. Any possible effects of the phenylalanine deficiency on other amino acids was obscured by the increased serum and urine concentrations of these amino acids resulting from increased intake provided by the proprietary casein hydrolysate preparation. Addition of valine, alanine, and methionine to the normal and deficient diets did not produce marrow changes or other toxic effects.

The authors gratefully acknowledge their indebtedness to Miss Meta Bohanan, R.N., and her staff for help in carrying out the observations on the patients and to Drs. H. P. Baker, R. Feigin, F. K. Kennedy, D. Palant, N. Pleva and P. Sexton of the resident staff for major contributions to the care and study of the patients.