Effect of oxygen tension and lactate concentration on keratan sulphate and chondroitin sulphate biosynthesis in bovine cornea

Calf cornea slices were incubated with [U- 14 C]glucose, in varying pO 2 or lactate concentrations. Acid glycosamino-glycans were separated by ion-exchange chromatography after papain digestion. The percentage radioactivity incorporated into keratan sulphate increased markedly with decreased oxygen tension, whereas a concomitant relative decrease of the biosynthesis of glycosaminoglycuronans occurred. Similar results were obtained with increased lactate concentration. Our findings support the idea that keratan sulphate is a functional substitute for chondroitin sulphate in conditions of oxygen lack (Scott, J.E. and Haigh, M. (1988) J. Anat. 158, 95–108).