The induction of phosphatase in various organs of the chick embryo

Abstract

1. 1. Various substrates were injected daily into chick eggs to test their inductive effect on phosphatases in the duodenum, liver, mesonephros, and metanephros of embryos between 14 and 19 days of incubation. 2. 2. Only phenyl phosphate administration significantly increased the activity of alkaline phosphomonoesterase in all organs studied. None of the substrates affected acid phosphomonoesterase activity. Adenosine-5-phosphatase activity was not affected by phenyl phosphate administration. 3. 3. Various observations indicate that the observed increase in alkaline phosphomonoesterase activity is to be taken as an actual synthesis of the enzyme. 4. 4. The patterns of alkaline phosphomonoesterase accumulation following phenyl phosphate administration were analyzed in detail. 5. 5. Histological and histochemical observations show that the induced alkaline phosphomonoesterase has an identical localization with the normal enzyme, and that the induced synthesis of the enzyme is dissociable from morphological differentiation of the organs to a considerable extent. 6. 6. The results obtained were discussed on the basis of the properties and suggested functions of phosphatases from an embryological viewpoint.