[Measurement of the hepatic, intestinal and bony fractions of the serum alkaline phosphatase (author's transl)].

A trial of thermostability associated with immunological estimation of alkaline phosphatase of intestinal origin permits evaluation of the various fractions of serum alkaline phosphatase. The usual values, drawn up on the basis of data collected in 35 subjects in apparently good health and chosen among a laboratory population, indicate that on average, 9 per cent of the enzyme activity is of intestinal origin whereas the hepatic and bony fractions are respectively 25 per cent and 67 per cent. On the basis of the results presented in this paper, it appears that the method proposed is able, in the presence of raised alkaline phosphatase, to determine the tissue origin of this blood abnormality. Whereas the coefficient of correlation drawn up between the values of 5-nucleotidase and those of the hepatic fraction of serum alkaline phosphatase determined by the technic described is satisfactory, if the raised alkaline phosphatase is of hepatic origin, it becomes poor or nil, if the latter is from an extra-hepatic source. In the cases of hyperphosphatasemia of extra-hepatic origin, there is excess evaluation of the hepatic alkaline phosphatase, if one concludes from the results of 5-nucleotidase.