Histochemical and biochemical study on acid phosphatase activity in differentiating liver of chick.

1. Acid phosphatase activity at different ontogenetic stages of liver in chick has been studied both by histochemical and quantitative biochemical methods. 2. It has been observed that the activity of acid phosphatase does not remain constant, but undergoes changes at different phases of epigenesis. The activity rhythmically becomes higher and lower throughout the whole period of epigenesis. Comparatively higher activities have been found up to 8 days of incubation, and then the activities become lower up to 14 days and again increased at later periods of development. 3. Higher acid phosphatase activity has been observed in the perivascular connective tissue than the parenchymal cells from the 8th to the 20th day of incubation. 4. The acid phosphatase activity is high in the nuclei of early developing red blood corpuscles, but in advanced stage of R.B.C. the phosphatase activity is very high in the cytoplasm, and it is practically absent in the nuclei. 5. The activity of acid phosphatase may have some relation with the cell death and catabolic processes during chick liver morphogenesis. The relation of the phosphatase activity with the growth and differentiation of the liver has been discussed.