In Vitro Incorporation of 14 C from 2- 14 C-Glucose into Rabbit Kidney Medullary and Duodenal Glycosaminoglycans 1

Abstract

Summary

Glycosaminoglycan concentrations in rabbit kidney medulla are 5.0 fold greater than in the kidney cortex. Rabbit kidney medullary tissue incubated in vitro with 2-¹⁴C-glucose, provides a crude fraction of glycosaminoglycans contaminated with ¹⁴C-glycogen. Following separation with CPC, the 1.² M NaCl fraction is recovered free of anthrone positive material and its radioactivity probably reflects ¹⁴C-glycosaminoglycan formation. The state of hydration of the rabbits or treatment with vasopressin does not change the radioactivity of the 1.2 M NaCl fraction. Duodenal glycosaminoglycans in the crude fraction as well as in both CPC fractions contain material having a high hexosamine/hexuronic acid molar ratio and high concentration of anthrone positive material which may indicate the presence of keratan sulfate. Glycosaminoglycan-containing fractions extracted from rabbit duodenal tissue which had been incubated with 2-¹⁴C-glucose have radioactivities 8 fold greater than those of kidney medullary glycosaminoglycans.