MEASUREMENT OF SYNTHESIS RATES OF LIVER-PRODUCED PLASMA PROTEINS

Abstract

RAT-INTESTINAL AMYLASES 277of the rice-starch solutions.This enzyme is acti- vated by Clions, inhibited by EDTA and does not hydrolyse disaccharides.Amylase B is responsible for only a small fraction of the total amylase activity of the mucosa, but accounts for about half of the amylase activity of the washed particles.It has the properties of a glucamylase (y-amylase; for a review see Lamer, 1960).Glucose is the primary reaction product of the action of a glucamylase on starch.Glucamylases are exoamylases, hydrolysing the terminal a- (1-4)-glucosidic linkages at the non-reducing end of starch chains.During its action the viscosity of a starch solution decreases very slowly.Amylase B also hydrolyses maltose to glucose at approxi- mately the same rate as starch is hydrolysed.It is responsible for about half of the maltase activity of the mucosal preparations.The physiological function of the intestinal glucamylase cannot be stated at present.Gluc- amylases have been demonstrated in mammalian liver (Glock, 1936; Torres & Olavarria, 1961;