Formalin-fixed and
paraffin-embedded canine brains were examined histochemically using 15 selected
lectins.
Concanavalin A (Con A),
Lens culinaris agglutinin, Lycopersicon esculentum
agglutinin (LEL) and Limulus polyphemus
agglutinin (LPA) labeled neurons in an age-dependent manner. These and some other
lectins [
Dolichos biflorus agglutinin (DBA),
Vicia villosa agglutinin (VVA),
Ricinus communis agglutinin 120 (RCA-I), Bandeiraea simplicifolia
agglutinin (BSL-I), and Phaseolus vulagaris
agglutinin-L (
PHA-L)] also age-dependently labeled glial cells. These results indicate that
monosaccharide composition and biochemical metabolism in brain cells change with age and that these
lectins may be useful as histochemical markers for investigating senile changes in the canine brain. However, no significant correlation was found between ApopTag-positive and
lectin-positive cells.
Amyloid plaques were positive for Con A, DBA,
Glycine maximus
agglutinin (SBA), LEL,
PHA-L,
Limax flavus agglutinin (LFA) and VVA. Among these
lectins, VVA, SBA and LFA intensely stained
amyloid both in blood vessel walls and
senile plaque cores. Therefore, the
sugar residues recognized by these
lectins likely play specific roles in
beta-amyloid deposition in the aged dog brain.