Mechanism of the change in shape of human erythrocytes induced by lidocaine.
We studied the mechanism of the lidocaine-induced shape change in human erythrocytes. Immunohistochemical analysis of erythrocytes using spectrin-specific antibodies revealed aggregation of fluorescence in lidocaine-treated cells, while the fluorescence was distributed diffusely in untreated cells. The intracellular pH in lidocaine-treated erythrocytes was examined by flow cytometry of the cells labeled with 3'-acetyl-2'-carboxy-ethyl-6',7'-(dihydropyran-2'-one)-5-carboxyfluoresc ein diacethoxymethylester (BCECF-AM), and was found to decrease with increasing concentrations of lidocaine. Pre-treatment of erythrocytes with acetazolamide, an inhibitor of carbonic anhydrase, inhibited the lidocaine-induced spectrin aggregation and decrease in intracellular pH. When erythrocytes were incubated in medium containing bafilomycin A1, an inhibitor of V-ATPase, followed by incubation with lidocaine, the cells changed shape slightly and the intracellular pH showed a small decrease in comparison with control. Spectrin dimers extracted from membranes normal erythrocytes were incubated in buffers of various pHs and analyzed by SDS-PAGE. The amounts of spectrin dimers and tetramers decreased, while that of oligomers increased with decreasing pH. These results suggest that the lidocaine-induced shape change in human erythrocytes may occur by the conformational change of spectrin in a process that may be mediated by carbonic anhydrase and activation of V-ATPase.
Nishiguchi
E
E
Department of Dental Hygiene, Shonan Junior College, Yokosuka, Japan.
Ozono
S
S
Takakuwa
Y
Y
Hamasaki
N
N
D048429:Cell Size / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects* / Q000502:physiology; D005456:Fluorescent Dyes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008012:Lidocaine / Q000494:pharmacology*; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D013049:Spectrin / Q000032:analysis*
D005456:Fluorescent Dyes; D013049:Spectrin; D008012:Lidocaine; D006180:Proton-Translocating ATPases