Changes in the distribution of sugar receptors in the brain of Mongolian hamster induced by 5-minute-long ischaemia.

The aim of the present study was to investigate the changes in the localisation of glycoconjugates caused by 5-minute-long ischaemia as a consequence of bilateral ligation of common carotid arteries. Histochemical evaluation was performed using specific lectins that recognize the following sugar residues: 1) alpha-D-galactosyl and N-acetylgalactosaminyl (Bandeiraea simplicifolia agglutinin, BS-I), 2) N-acetyl-beta-D-galactosaminyl (Ricinus communis, agglutinin, RCA-60), 3) N-acetyl-alpha-D-galactosaminyl (Helix pomatia agglutinin, HPA), 4) alpha-D-mannosyl and alpha-D-glucosyl (Concanavalin A), 5) alpha-D-fucosyl (Tetragonolobus purpureas agglutinin, TG). It was found that the first two lectins (Bandeiraea simplicifolia and Ricinus communis) bound selectively to endothelium, while two others (Helix pomatia and Concanavalin A) showed affinity predominantly to cellular compartments of the brain, like neurons and glia, but also to neuropil and the white matter. Tetragonolobus purpureas agglutinin did not stain any brain structures. Significant changes in the arrangement of examined glycoconjugates as a result of ischaemia were observed. First, the intensity of binding of BS-I and RCA-60 to their complementary residues was increased in the capillary network as compared with control animals. Glycoconjugates recognised by these lectins were also found in reactive astrocytes in various brain structures. Second, the number of sugar receptors visualised by Con A and HPA was enhanced in the majority of cellular compartments of the brain and, though to a lesser extent, in terminal capillary network, especially in the neocortex, while in control animals these sugar receptors were detected in brain microvessels. Redistribution of particular sugar residues after ischaemia suggests that functional changes associated with this type of injury might take place in various CNS structures.