Isolation and characterization of glycosaminoglycans in brain of different species.

s-The uronic acid-containing glycosaminoglycans present in the brains of rat, monkey, chicken, sheep and rabbit were isolated into various fractions by combining the cetyl pyridinium procedure and DEAE-Sephadex column Chromatography. The analyses of the fractions show that hyaluronic acid, chondroitin4sulphate, chondroitin-6-sulphate, heparan sulphate and a testicular hyaluronidase-resistant galactosamine-containing GAG are present in the brain of all the species studied. Hyaluronic acid is the major GAG (3341 per cent). Chondroitin4sulphate (19-35 per cent), and heparan sulphate (1 1-19 per cent), are the next prominent GAGs, in all the species except chicken. The results indicate the similarity in the pattern of GAGS in the brain of all the species. IN RECENT years, a number of reports have appeared regarding the nature of glycosaminoglycans (GAGs) in the central nervous system (MEYER, HOFFMAN, GRUMBACH and SAMPSON, 1959; Szmo and ROBOZ-EINSTEIN, 1962; CLAUSEN and HANSEN, 1963; SINGH and BACHHAWAT, 1965; MARGOLIS, 1967). The variation in the pattern of GAGS in different species was indicated by the work of ONODERA, HIRANO, HORIUCHI and KASHIMURA (1966) who showed that bovine brain contains hyaluronic acid, chondroitin-4-sulphate and chondroitin-6-sulphate and that monkey brain contains hyaluronic acid and chondroitin-6-sulphate whereas chondroitin-4-sulphate and chondroitin-6-sulphate are present in the brain of pig and rabbit respectively. The work of MARG~LIS (1967) showed the presence of hyaluronic acid, chondroitin-4-sulphate and chondroitin-6-sulphate in bovine whole brain and the absence of GAGS from bovine myelin. Recent work from this laboratory (SINGH and BACHHAWAT, 1968) on the GAGS of human brain indicated the presence of hyaluronic acid, chandroitin-4sulphate, chondroitin-6-sulphate, dermatan sulphate, heparan sulphate and lowsulphated GAGs. These studies, which employed different procedures for the isolation of GAGs, indicate the variation in the pattern of GAGS in different species. In the present investigation, the nature and level of uronic acid-containing GAGS in the brain of the different species rat, monkey, man, chicken, sheep and rabbit are reported by employing the cetylpyridinium procedure and then DEAE-Sephadex chromatography for the isolation of GAGs. MATERIALS A N D METHODS Glucosamine-HCl, galactosamine-HCI, hyaluronic acid and testicular hyaluronidase type I were obtained from Sigma Chemicals, U.S.A., chondroitin-6-sulphate from Miles Research Laboratory, U.S.A. and cetyl pyridinium bromide from Mann Research Laboratories. Sephadex G-25 and DEAE-Sephadex A-25 were supplied by Pharmacia Uppsala, Sweden. Papain (crude) was a gift from The Central Food Technological Research Institute, Mysore, India, and pronase B was obtained from California Biochemical Corporation, U.S.A. All the chemicals used were of analytical grade. Abbreviation used: GAG, glycosaminoglycan.