Deficient 21-hydroxylase activity prevents the synthesis of aldosterone ... in maintenance doses of 10 to 20 mg per square meter of body-surface area per day in three divided doses.

First, tetrahydrobiopterin loading led to normal or nearly normal blood phenylalanine concentrations in most patients with residual phenylalanine hydroxylase activity, suggesting that ...

Cases 3 and 4 may be viewed as hyperphenylalanemia without PKU. Phenylalanine hydroxylase was determined by the method of LaDu and Zannoni and fresh liver obtained by biopsy. The results expressed ...

The enzyme phenylalanine hydroxylase is almost exclusively limited to the liver although some activity may be found in the kidney and the intestinal mucosa. Determination of this enzyme activity ...