THE DISTRIBUTION OF RADIOACTIVE CARBON FROM [U-¹⁴C] GLUCOSAMINE IN MICE

Abstract

Tissue and organ distribution of radioactive carbon from ¹⁴C-labeled glucosamine in the mouse was studied by whole-body autoradiography and biochemical analysis. The mice injected intraperitoneally with D-[U-¹⁴C]-glucosamine were sacrificed at various intervals. Examination of autoradiographs disclosed that the injected ¹⁴C-glucosamine was almost completely absorbed from the abdominal cavity 30min after injection. At 5min after injection, the highest radioactivity was observed in the liver, but the activity in the blood and brain was low. The radioactivity in these organs was made negligible by perchloric acid treatment of sections. At 30min after injection, high radioactivity was detected in the liver, small intestine, preputial gland and urine. At 3hr after injection, the liver, blood and cortex of the kidney had high radioactivity.
The comparative values among radioactivity in various organs estimated by a liquid scintillation counter were consistent with those obtained from whole-body autoradiographs. At 30min after injection, an increase of radioactivity in the acid-insoluble fractions was observed in all organs examined. In animals at 5 and 30min after injection, paper chromatography of the acidsoluble fractions disclosed radioactive spots for glucosamine and N-acetyl-glucosamine in the blood, N-acetylglucosamine and glucose in the kidney and glucosamine, glucuronic acid and glucose in the liver. By gel electrophoresis, a radioactive protein with molecular weight of 90, 000 was detected in the acid-insoluble fraction of kidney at 30min after injection.