BIOCHEMICAL PROPERTIES OF FRACTIONS OBTAINED FROM RAT ANTERIOR PITUITARY GLANDS BY DIFFERENTIAL CENTRIFUGATION¹

Abstract

THE biochemistry of the nuclear, mitochondrial, microsomal and supernatant fractions isolated by differential centrifugation from rat and mouse liver has been studied extensively during the past few years. Particular attention has been given to the distribution of the oxidative enzymes and nucleic acids among these fractions. Respiratory enzymes such as cytochrome oxidase and the succinoxidase system have been found to be associated with the mitochondrial fraction (Schneider, 1946; Hogeboom et al., 1946 and 1948). The microsomalfraction contains few enzymes but as much as 50% of the pentosenucleic acid of liver tissue (Hogeboom et al., 1948; Schneider et al., 1950.) The results of studies of this nature have been summarized by Schneider and Hogeboom (1951). Little attention has been given to the biochemical and hormonal properties of fractions of endocrine tissues isolated by differential centrifugation. Approximately 60% of the succinoxidase activity of rat anterior pituitary glands, however, has been reported to be associated with a large granule fraction (McShan and Meyer, 1949)