BLOOD CARBONIC ANHYDRASE ACTIVITY IN NEWBORN INFANTS AND THEIR MOTHERS

Each ml.of erythrocytes of newborn infants exhibits carbonic anhydrase activity which, on the average, is approximately 40% of that found in the erythrocytes of adult subjects. The deficiency appears to vary with the maturity of the organism, either in or ex utero. It is not as great as that described by earlier workers who used methods of less validity. Moreover, the relative polycythemia of the newborn infant counteracts this deficiency, and accordingly the blood of these infants may exhibit carbonic anhydrase activity within or a little below the normal adult range. Transfusion into infants of adult blood increases the carbonic anhydrase activity. Mothers in whom blood hemoglobin levels are low show similar degrees of lowering of blood carbonic anhydrase activity. The functional significance of the changes found in the newborn infant is not known.