CHANGES IN GLYCOSAMINOGLYCANS DURING REGENERATION OF POST-CRUSH SCIATIC-NERVES OF ADULT GUINEA-PIGS

The glycosaminoglycans of sciatic nerves recovering from crush-injury were studied in adult guinea pigs and compared with those of non-injur ed mature neural tissues, The glycosaminoglycans were recovered from t he 1,900 g supernatant and pellet of the tissue homogenates and assaye d for hexuronate contents and susceptibilities to hyaluronidase, chond roitinase ABC, and nitrous acid, In the normal brain and central nerve tracts, the glycosoaminoglycans were distributed both in the supernat ant and pellet fractions; the brain showed a predominance of chondroit in sulphates but the tracts showed a predominance of heparan sulphates , Twice as much glycosaminoglycans were found in normal sciatic nerves , only in the pellet fraction and with heparan sulphate predominant, I n the 2 weeks post-crush, progressive increase in hexuronate was obser ved, due mainly to additional chondroitin sulphate forms in the supern atant; the pellet fraction in the same period was however similar to t he untreated controls in relative abundance of glycosaminoglycan class es and hexuronate content, At 4 weeks post-crush, although the total h exuronate returned to the control level, a significant proportion of g lycosaminoglycans remained in the supernatant fraction, Evidence is th us provided for the need to modulate the glycosaminoglycan expression pattern in adult neural tissue to allow post-traumatic tissue remodell ing and axonal regrowth. (C) 1996 Wiley-Liss, Inc.