[Content of N-acetylneuraminic acid in water-soluble and membrane fractions of various fractions from rat brain cortex].

The content of N-acetylneuraminic acid (ANA) was measured in the water-soluble and membrane fractions of the visual, locomotory, auditory and sensomotory divisions of rat brain cortex as well as in glycoproteins and glycolipids of the membrane fraction. The content of ANA in the water-soluble fraction of the visual, locomotory, auditory and sensomotory analyzers of brain cortex was 0.55, 0.56, 0.55 and 0.65 mkg/mg of dry weight, respectively. The ANA content in the membrane fraction was 9.2, 8.8, 8.2 and 8.4 mkg/mg of dry weight, respectively. The ANA content in the membrane fraction of glycoproteins was 2.8, 2.4, 2.2 and 2.8 mkg/mg of dry weight, respectively., that in the membrane fraction glycolipids--5.2, 7.2, 5.9 and 5.5 mkg/mg of dry weight, respectively. The ANA content in the membrane glycolipids of the locomotory division of rat brain cortex differed significantly from that of all the other divisions.