The significance of phosphatase estimations in the adult fowl

showed that in certain bone diseases in man the plasma-phosphatase activity is considerably higher than normal. This served as an impetus for investigation into the activity of the enzyme in plasma and tissues under different conditions in man and experimental animals. The literature has been reviewed by Briefly, it may be said that in healthy young animals the activity of the plasma-phosphatase is higher than it is in the adult, but with the completion of rapid bone formation the value drops to the adult level. This is well illustrated by the observations of Stearns and Warweg [1933] with children. During the healing of rickets or other bone diseases the initially high plasma-enzyme activity tends to return to the normal for animals of that age and class. Ab- normally high values may be observed in jaundice When proper precautions are taken it would seem that estimation of the plasmaphosphatase activity may serve in many mammals as a somewhat earlier indica- tion of faulty Ca and P metabolism than do serum-Ca or inorganic P determina- tions, although high phosphatase values cannot be considered specific for any one disease.