Tissue alkaline phosphatase activity in selected freshwater teleosts

1. Kinetic studies of tissue alkaline phosphatase activity were carried out on eight species of teleost fishes taken from the Mississippi River. 2. Liver alkaline phosphatase activity expressed in mumoles of p-nitrophenol released per minute per gram of protein were as follows: Micropterus salmoides, 20.31; Stizostedion vitreum, 19.22; Pomoxis nigromaculatus, 18.76; Lepisosteus platostomus, 16.26; Esox lucius, 16.14; Hiodon tergisus, 13.83; Ictalurus punctatus, 10.87; Aplodinotus grunniens, 7.94. 3. Specific activity of the kidney alkaline phosphatase was about ten times the level of liver alkaline phosphatase for the species examined.