Atomic Force Microscopy and High-Resolution Spectrophotometry for Study of Anoxemia and Normoxemia in Model Experiment In Vitro

Abstract

The oxygen content in the blood may decrease under the influence of various physicochemical factors and different diseases. The state of hypoxemia is especially dangerous for critically ill patients. In this paper, we describe and analyze the changes in the characteristics of red blood cells (RBCs) with decreasing levels of oxygen in the RBC suspension from normoxemia to hypoxemia/anoxemia in an in vitro model experiment. The RBCs were stored in hypoxemia/anoxemia and normoxemia conditions in closed and open tubes correspondingly. For the quantitative study of RBC parameter changes, we used atomic force microscopy, digital spectrophotometry, and nonlinear curve fitting of the optical spectra. In both closed and open tubes, at the end of the storage period by day 29, only 2% of discocytes remained, and mainly irreversible types, such as microspherocytes and ghosts, were observed. RBC hemolysis occurred at a level of 25–30%. Addition of the storage solution, depending on the concentration, changed the influence of hypoxemia on RBCs. The reversibility of the change in hemoglobin derivatives was checked. Based on the experimental data and model approach, we assume that there is an optimal level of hypoxemia at which the imbalance between the oxidative and antioxidant systems, the rate of formation of reactive oxygen species, and, accordingly, the disturbances in RBCs, will be minimal.

Red Blood Cell Storage with Xenon: Safe or Disruption?

“…The functionality of both oxidant and antioxidant systems is influenced by the concentration of oxygen. As we have described previously [ 35 ], an optimal level of oxygen exists that promotes redox equilibrium. It is important to note that even a small shift in the ratio of gases, such as oxygen and xenon, from the optimal value will change the reactive oxygen species formation rate and, consequently, their levels.…”

“…By day 42, discocytes had irreversibly transformed into spheroechinocytes and spherocytes, ultimately becoming erythrocyte ghosts. This pattern of cell shape changes is indicative of erythrocyte aging and prolonged storage of donor erythrocytes [ 27 , 28 , 35 , 45 , 46 ].…”

“…Our approach also takes into account scattering processes. More details can be found in our previous work [ 35 ].…”

Hemoglobin Derivatives in Beef Irradiated with Accelerated Electrons

“…where l is the number of wavelengths; ε Hb,l (λ l ), ε HbO 2 ,l (λ l ), and ε MetHb,l (λ l ) are molar absorption coefficients of deoxyhemoglobin, oxyhemoglobin, and methemoglobin, respectively; C Hb , C HbO 2 , and C MetHb are the concentrations of deoxyhemoglobin, oxyhemoglobin, and methemoglobin, respectively; L = 1 cm is the thickness of the solution layer; E and K are scattering coefficients [25,40]. According to the current research literature, the molar absorption coefficient of beef erythrocyte hemoglobin derivatives practically coincides with those of human hemoglobin [48].…”

“…It is known that hemoglobin derivatives in red blood cells are sensitive to physical and chemical factors, such as irradiation and the presence of toxins in blood [24], oxygen content [25], and other factors both in vivo and in vitro [26].…”