UPTAKE OF RADIOACTIVE SULPHUR BY VARIOUS TISSUES OF NORMAL AND CHOLESTEROL-FED RABBITS

Abstract

The uptake of inorganic sulphur labelled with radioactive sulphate (S35) was studied in rabbits that had been fed a normal diet and rabbits that had been fed a similar diet supplemented by the addition of 1% of cholesterol for 4 months. Paper electrophoresis of alkaline extracts of cartilage, tendon, or aorta separated a peak of radioactivity that corresponded to a band that stained metachromatically with toluidine blue and that is assumed to be chondroitin sulphate. Characteristic peaks of radioactivity were found by electrophoresis of extracts of mucin-containing tissues of the gastrointestinal tract, indicating the location of sulphated mucus with a mobility different from that of chondroitin sulphate. No radioactive material was isolated from the tissues of cholesterol-fed animals that was not present in normal tissues. Highly significant over-all differences in specific activity of sulphur were found between various tissues in both normal and cholesterol-fed rabbits. A significant elevation of both specific activity and sulphur concentration was produced in the aorta as a result of cholesterol feeding.