Phytase in Plasma and Erythrocytes of Various Species of Vertebrates

A phytic acid-splitting enzyme, called phytase, was first found in rice bran by Suzuki et al. (l), and phytases were found later in various plant materials (2).The occurrence of phytase in the animal kingdom was reported by McCollum and Hart (3), who found phytase activity in the liver and blood of calves.However, Plimmer (4) and other investigators (5) failed to find the enzyme in extracts of intestines, pancreas, kidney, bones, and also the liver and blood of several species of animals.Recently Patwardhan ( 6) reported some phytase activity in extracts of rat intestines, but little if any activity was found in the intestines of guineapigs and rabbits and in bone extracts of all animals studied.After the finding of phytic acid in the bloods of birds and turtles (7), we examined the blood plasmas and cells of fourteen species of animals for phytase activity and undertook a general survey of the properties and kinetics of this enzyme.EXPERIMENTAL Plasma Phytase-Blood samples, drawn with a needle and glass syringe from the wing vein of birds, and by heart puncture from rabbits, frogs, snakes, turtles, and fish, were collected in vials containing heparin.Calf blood was obtained at the slaughter-house, defibrinated, and transported quickly to the laboratory.After centrifugation the plasma was kept for 30 minutes in a desiccator over concentrated NaOH to remove most of the COZ, and then an exactly measured volume was mixed with an equal volume of a 0.5 per cent solution of pure recrystallized sodium phytate which had been adjusted to pH 7.2. 1 cc. of this plasma-substrate mixture was precipitated immediately with 2 cc. of 20 per cent 621