RESUMO
Changes in the refractive index of the cytoplasm and the affinity of haemoporphyrin of erythrocyte haemoglobin to oxygen (pH, 2,3-diphosphoglycerate) have been investigated using laser interference microscopy and Raman spectroscopy. It has been established that a decrease in pH and an increase in the content of 2,3-diphosphoglycerate are accompanied by changes in both the form of the cell and the refractive index of the cytoplasm and the affinity of haemoporphyrin of hemoglobin to oxygen. It has been shown that as pH is reduced, the capacity of haemoporphyrin for binding oxygen decreases and as the concentration of 2,3-diphosphoglycerate is increased, the ability of haemoporphyrin for oxygen reabsorption increases.
Assuntos
Citoplasma/ultraestrutura , Eritrócitos/metabolismo , Hemoglobinas/metabolismo , Oxigênio/metabolismo , 2,3-Difosfoglicerato/farmacologia , Forma Celular , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Líquido Extracelular/química , Hematoporfirinas/química , Hematoporfirinas/metabolismo , Hemoglobinas/química , Humanos , Concentração de Íons de Hidrogênio , Microscopia Confocal , Microscopia de Interferência , Conformação Proteica , Análise Espectral RamanRESUMO
Morphobiochemistry of erythrocytes, erythropoiesis intensity (determined by iron metabolism and erythropoietin content), lipids and phospholipids of erythrocyte plasmatic membrane and oxygen binding and release by hemoglobin were studied in normal male volunteers for 7-d dry immersion. Investigations were performed before the experiment, on the last day in immersion (d-7) and on days 7 and 15 of recovery. After 7-d dry immersion, the volunteers exhibited a trend towards changes in red blood morphology, erythropoiesis intensity, and erythrocyte metabolism. Seven-day simulation of microgravity alters significantly the oxygen-transporting function of erythrocytes. This is, probably, associated with shifts in the cell membrane evidenced by apparent changes in phospholipids fractions. These changes have no clinical significance as concluded from reestablishment of most of the parameters by day 15 of recovery. The broad variability of measured values is attributed to individual character of body response to the stresses of the experiment.
Assuntos
Eritrócitos/fisiologia , Eritropoese/fisiologia , Eritropoetina/sangue , Hemoglobinas/metabolismo , Imersão , Fosfolipídeos/sangue , Recuperação de Função Fisiológica/fisiologia , Adulto , Seguimentos , Humanos , Masculino , Oxigênio/sangue , Valores de Referência , Adulto JovemRESUMO
Plasmatic membrane viscosity and permeability and hemoporphyrine conformation in human hemoglobin were studied on completion of long-duration space flight (LSF). Reversible increases in viscosity and selective permeability (Na+/H+ -turnover) of erythrocyte plasmatic membrane were observed immediately after and in the period of recovery from LSF. Viscosity of lipids in both external and internal locations of plasmatic membrane in human erythrocytes was changed after LSF. The reversible rise of the Na+/H+ -turnover is likely to alter intracellular pH and oxygen binding with hemoglobin. The former is confirmed by the concurrent reversible decline in the deoxyhemoglobin ability to bind oxygen and the oxyhemoglobin ability to retain oxygen. In LSF and during readaptation to the normal gravity blood levels of hemoglobin and free iron are known to be reduced and may be answerable for the hypoxic state of human organism.