EVALUATION OF THE GLYCOGENOLYTIC EFFECT OF α-AMYLASE USING RADIOAUTOGRAPHY AND ELECTRON MICROSCOPY

Abstract

The effectiveness of crystalline α-amylase and saliva in hydrolyzing newly formed glycogen in liver and muscle was examined. Glycogen synthesis was induced by the administration of H³-glucose to fasting rats or by the incubation of tissue slices in a medium containing H³-glucose. Paraffin sections of Rossman-fixed tissues or small pieces of liver fixed in glutaraldehyde and subsequently postosmicated and embedded in Epon were then enzymatically digested. Grain counts were made in radioautographs of treated and untreated materials, and the amount of radioactivity removed by the digestion was used to assess the efficiency of the enzymes in hydrolyzing glycogen. Crystalline α-amylase hydrolyzed almost completely newly formed glycogen in liver and muscle. Saliva removed the glycogen that was synthesized in vivo, but it was less effective in hydrolyzing glycogen synthesized in vitro. Electron micrographs of digested liver cells confirmed the radioautographic findings on the effectiveness of the enzyme preparations.