IMPAIRED MYELIN FORMATION IN EXPERIMENTAL HYPERPHENY LALANINAEMIA¹

Abstract

Abstract— From the 5th to the 20th postnatal day, rats were injected with saline (controls) or phenylalanine (3 mg/g daily). The quantities of cholesterol and glycolipids were significantly lower in the phenylalanine‐injected rats, but brain DNA and protein contents were the same in both groups. As a result of the reduced formation of lipids, the hyperphenylalaninaemic brains contained significantly less myelin than control brains, but the gross composition [ratio of protein: cholesterol: galactolipid: phospholipid) of the myelin was unchanged. We suggest that in hyperphenylalaninaemic brains the reduced availability of cholesterol may cause a reduction in the formation of cholesterol‐phospholipid‐protein complexes in brain, which in turn may limit the formation of myelin.