title: Topo-optical investigations of the conformational change of the erythrocyte glycocalyx in dependence on extracellular pH and presence of dextran.
abstract: The erythrocyte (RBC) glycocalyx reacts very sensitively to environmental influences. But few is known about the effects of certain factors, which can change the membrane structure. Therefore we have tried to investigate in model experiments by means of the topo-optical toluidine blue reaction the conformational changes of the RBC glycocalyx in dependence on pH (range from 7.5 to 4.5) and presence of dextran. The findings, which are presented here, demonstrate a high sensitivity of the glycocalyx to pH influences. A distinct drop of the membrane anisotropy can be observed in the pH range from 6.5 to 4.5. Also dextran molecules evidently cause structural changes of the RBC glycocalyx via interaction with H-bonds. On the basis of a hypothetical structural model of the glycophorins outer segment the conformational effects are discussed.
mesh_terms: D003911:Dextrans / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000648:ultrastructure*; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011134:Polysaccharides / Q000097:blood*
chemical_list: D003911:Dextrans; D006023:Glycoproteins; D011134:Polysaccharides