Carbohydrate metabolism in normal and thyroidectomized Bufo bufo adult males

Abstract

1. 1. In adult male specimens of Bufo bufo, thyroidectomized by means of 131I administration, the blood-glucose level dropped 55 per cent below that in the normal toad. 2. 2. In the liver the rate of synthesis of lactate from glucose and glycogen, under anaerobiosis, is slowed down; the same is true for the velocity of hexokinase and phosphorylase reactions. 3. 3. There is no change in the activity of phosphoglucomutase, aldolase, triose-phosphate isomerase, glyceraldehydephosphate dehydrogenase, phosphoglycerate kinase, enolase, pyruvate kinase and lactate dehydrogenase. 4. 4. Increase in both the phosphofructokinase activity and glycogen storage are seen to occur. 5. 5. Among the enzymes involved in the gluconeogenesis pathway, hexosediphosphatase appears unaltered, whilst glucose-6-phosphatase is inhibited up to 50 per cent.