title: Membrane damages under high pressure of human erythrocytes agglutinated by concanavalin A.
abstract: Human erythrocytes are agglutinated by lectins such as concanavalin A (Con A). The behaviors of agglutinated erythrocytes under pressure are less well understood. Here, we report the effects of erythrocyte agglutination on pressure-induced membrane damages. Small clumps of intact erythrocytes by Con A were dissociated by a pressure of 200 MPa. Further, the observation by scanning electron microscopy demonstrated the generation of vesicles, fragmented particles, and membrane hole. On the other hand, large clumps of trypsin-digested erythrocytes by Con A seemed to be stable against 200 MPa. However, the erythrocytes dissociated from such pressure-treated clumps by methyl α-mannopyranoside also showed the existence of vesicles and fragmented particles except for the membrane hole. Pressure-induced hemolysis was greatly suppressed in such large clumps. Similar suppressive effects were observed in erythrocytes packed by centrifugation. However, the hemolysis occurred when the erythrocytes dissociated from 200 MPa-treated large clumps by methyl α-mannopyranoside were incubated at 0°C and atmospheric pressure. Pyrene excimer fluorescence due to spectrin denaturation was observed in Con A-agglutinated ghosts that were exposed to a pressure of 200 MPa. These results suggest that upon pressure treatment of tightly agglutinated erythrocytes, the hemolysis is greatly suppressed, but membrane damages occur such as spectrin denaturation and vesiculation.
authors.affiliation: Department of Chemistry, Faculty of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan. Electronic address: takeo@fukuoka-u.ac.jp.
authors.forename: Takeo
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Department of Chemistry, Faculty of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Tajiri
authors.affiliation: Center of Electron Microscopy, Faculty of Medicine, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Murata
authors.affiliation: Department of Chemistry, Faculty of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan.
authors.forename: Shigemi
authors.initials: S
authors.lastname: Nagadome
mesh_terms: D002450:Cell Communication / Q000187:drug effects*; D003208:Concanavalin A / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000187:drug effects*; D004912:Erythrocytes / Q000187:drug effects*; D006801:Humans; D011312:Pressure; D013329:Structure-Activity Relationship
chemical_list: D003208:Concanavalin A
keywords: Agglutination; Concanavalin A; Erythrocyte; Hemolysis; Spectrin; Vesiculation