IDENTIFICATION OF CAPILLARIES IN SECTIONS FROM SKELETAL-MUSCLE BY USEOF LECTINS AND MONOCLONAL-ANTIBODIES REACTING WITH HISTO-BLOOD GROUP ABH ANTIGENS

This study was performed to evaluate the application of different lect ins and monoclonal antibodies against ABH antigens to detect and chara cterize carbohydrate structures in capillaries of skeletal muscle from humans and laboratory animals. Blood group specific lectins (Griffoni a simplicifolia, Griffonia simplicifolia isolectin B4, Lotus tetragono lobus, Ulex europaeus, and Dolichos biflorus) and monoclonal antibodie s reacting with histo-blood group carbohydrate antigens belonging to t ype 1 (Le(a)) and type 2 (H, A and Le(y)) chains were used as histolog ical markers for capillaries in sections from skeletal muscle. The mat erial consisted of 20 human masseter muscle biopsies from individuals with known blood types: (eight blood group 0, nine blood group A, two blood group B, and one blood group AB) and masseter muscles specimens from different laboratory animals (mouse, rat, rabbit, cat, dog, pig, cow, and macaca monkey). Unfixed sections and an avidin alkaline phosp hatase method were used to visualize the specific reaction. Ulex lecti n stained capillaries in all human biopsies either strongly or moderat ely. Strong muscle capillary reaction was observed in biopsies from 0, B and AB individuals while capillaries from A individuals were only m oderately stained. Griffonia simplicifolia marked capillaries in A, B, and AB individuals and Griffonia simplicifolia isolectin B4 stained c apillaries in muscle biopsies from B and AB donors. Dolichos biflorus was a weak marker of muscle capillaries from A individuals. Only capil laries from O individuals were stained with the antibody against H typ e 2. Capillary reaction was not observed with the other antibodies use d. Girffonia simplicifolia was an excellent marker for capillaries in mouse muscle while Griffonia simplicifolia isolectin B4 is recommended for rat muscles. Periodic acid treatment and subsequent Lotus tetrago nolobus staining is suitable to visualize capillaries in mouse, rat an d pig muscle. Using a sensitive histochemical technique for staining w ith lectins and monoclonal antibodies reacting with blood group relate d antigens the microvascular density in human skeletal muscle may be e stimated. Further, the carbohydrate compounds in the muscle capillarie s reflect the individual blood type. A selection of lectins is suitabl e for demonstration of capillaries in animal skeletal muscle.