CARNOSINE-SYNTHESIS IN CULTURES OF RAT GLIAL-CELLS IS RESTRICTED TO OLIGODENDROCYTES AND CARNOSINE UPTAKE TO ASTROCYTES

Cultures of glial cells consisting predominantly of oligodendrocytes a nd astrocytes were prepared to study whether the biosynthesis of carno sine (beta-Ala-His) and the cellular uptake of this dipeptide are proc esses which are associated with a specific cell type. Uptake of the ra diolabeled precursor beta-alanine was observed in both cultures. Synth esis of radiolabeled carnosine, however, was only observed in oligoden drocyte cultures prepared from rat brain and spinal cord. During oligo dendrocyte cultivation we observed a significant increase in the rate of carnosine synthesis which correlates with the differentiation of th ese cells as revealed by immunostaining with antibodies against oligod endrocyte markers. Carnosine synthesis was not observed in astroglia c ell cultures that were depleted of residual O2-A progenitor cells and oligodendrocytes by antibody mediated complement cell killing. Contrar y to the synthesis, carnosine was found to be taken up effectively onl y by astrocytes but not by oligodendrocytes.