RESUMEN
Measuring the impedance of heated suspensions of erythrocytes and erythrocyte ghost membranes, two thermally-induced alterations are registered in the plasma membrane at TA (denaturation of spectrin with inducing temperature at 49,5⯰C) and TG (hyperthermic activation of basal ion permeability with inducing temperature at 60.7⯰C). In this study erythrocytes from 9 healthy patients and 15 patients with hemolytic anemia were studied and divided into four groups depending on their TA and TG top temperatures. The TA and TG of erythrocytes with hemoglobinopathy were the same as those of control erythrocytes while those of erythrocytes with membranopathy were significantly reduced. In erythrocytes with severe membranopathy, the TG was decreased by about 5⯰C. In latter cells the normal value of TG was restored and the resistance to thermal haemolysis was increased by 90% after the specific stabilization of band 3 protein by 4,4'-diisothiocyanato-stilbene-2,2'-disulfonic acid (DIDS). Obtained results indicate the involvement of band 3 in the membrane alteration at TG and in the heat target responsible for thermal haemolysis.
Asunto(s)
Anemia Hemolítica/metabolismo , Anemia Hemolítica/patología , Membrana Eritrocítica/metabolismo , Membrana Eritrocítica/patología , Hemólisis , Calor , Proteína 1 de Intercambio de Anión de Eritrocito/metabolismo , Humanos , Espectrina/metabolismoRESUMEN
Hereditary hemolytic anemias originate mainly from defects in hemoglobin and plasma membrane proteins. Here, we propose a new method, thermal analysis of impedance, sensitive to membrane defects. It detects three processes in erythrocyte membrane; fall in membrane capacity at 49.5 degrees C and activation of passive PO(4)(2+) permeability at 37 degrees C and inorganic ions at 61.5 degrees C. The denaturation of spectrin is involved in the first process whilst the anion channel is involved in latter processes. Using this method three persons with xerocytosis were found whereby the fall in membrane capacity and spherization of erythrocytes were both postponed (53 degrees C) compared to control (49.5 degrees C). In contrast to control cells, strong activation of passive permeability for Cl(-) at 37 degrees C and sucrose at 61 degrees C were detected that were both eliminated by pre-inhibition of the anion channel with 4,4'-diisothiocyanato-stilbene-2,2'-disulfonic acid (DIDS). In addition, erythrocytes from 15 patients with various forms of anemia were studied in intact state and after refreshment. The results were compared with the data of clinical laboratory and osmotic fragility test. The final conclusion is that this method detects membrane defects with altered spectrin and anion channel syndrome (hereditary xerocytosis, spherocytosis, poikilocytosis and pyropoikilocytosis, elliptocytosis and stomatocytosis) and, after refreshment, helps differentiate them from the anemia with hemoglobinopathy.