In this work we applied a multimodal approach to define the age- and atherosclerosis-related biochemical and functional alterations in red blood cells (RBCs) in ApoE/LDLR^-/- mice. Our results revealed that age-related changes in RBCs, such as decreases in RBC deformability and mean height, were more pronounced in ApoE/LDLR^-/- mice than in age-matched control mice (C57BL/6J). The decreases in phospholipid content and level of lipid unsaturation were accompanied by an increase in cholesterol esters and esterified lipids in RBC membranes in aged C57BL/6J mice. The age-related decrease in the phospholipid content was more pronounced in ApoE/LDLR^-/- mice. In contrast, the increase in the total lipid content in RBC membranes occurred only in ApoE/LDLR^-/- mice with advanced atherosclerosis. The age-related alterations also included a decrease in the ratio of turns to α-helices in the secondary structure of hemoglobin (Hb) inside intact RBCs. On the other hand, an increase in the ratio of unordered conformations to α-helices of Hb was observed only in ApoE/LDLR^-/- mice and occurred already at the age of 5-weeks. This was related to hypercholesterolemia and resulted in an increased oxygen-carrying capacity. In conclusion, progressive mechanical and functional alterations of RBCs in aged ApoE/LDLR^-/- mice were more pronounced than in age-matched C57BL/6J mice. Although, several biochemical changes in RBCs in aged ApoE/LDLR^-/- mice recapitulated age-dependent changes observed in control mice, some biochemical features of RBC membranes attributed to hypercholesterolemia were distinct and could contribute to the accelerated deterioration of RBC function in ApoE/LDLR^-/- mice.

Based on the multimodal characterization of human red blood cells (RBCs), the link between the storage-related sequence of the nanoscale changes in RBC membranes in the relation to their biochemical profile as well as mechanical and functional properties was presented. On the background of the accumulation of RBCs waste products, programmed cell death and impaired rheological properties, progressive alterations in the RBC membranes including changes in their height and diameter as well as the in situ characterization of RBC-derived microparticles (RMPs) on the RBCs surface were presented. The advantage of atomic force microscopy (AFM) in RMPs visualization, even at the very early stage of vesiculation, was shown based on the results revealed by other reference techniques. The nanoscale characterization of RMPs was correlated with a decrease in cholesterol and triglycerides levels in the RBC membranes, proving the link between the lipids leakage from RBCs and the process of vesiculation.

The study assessed the effect of 3-week intermittent hypoxic training on blood biochemical indicators (blood morphology, fibrinogen), blood rheological properties (erythrocyte deformability, aggregation), erythrocyte enzymatic activity (acetylcholinesterase), and maximal oxygen uptake in competitive rowers. Fourteen male rowers were divided into two equal groups: experimental, training on ergometers under normobaric hypoxia (FiO₂ = 16.0%), and control, training on ergometers under normoxia (FiO₂ = 21%). Fasting blood was taken before and after training. A significant between-group difference in neutrophil levels before training was noted and a significant decrease in white blood cells in the hypoxia group. Both groups exhibited an increase in elongation index. In the normoxia group, a significant increase in erythrocyte aggregation amplitude was revealed. No significant changes occurred in the other biochemical indicators or those evaluating erythrocyte metabolic activity. Normobaric hypoxia increased erythrocyte deformability, improving blood rheological properties. Maximal oxygen uptake significantly increased only in the experimental group.

Background: Acid–base balance (ABB) is a major component of homeostasis, which is determined by the efficient functioning of many organs, including the lungs, kidneys, and liver, and the proper water and electrolyte exchange between these components. The efforts made during competitions by combat sports athletes such as kickboxers require a very good anaerobic capacity, which, as research has shown, can be improved by administering sodium bicarbonate. Combat sports are also characterized by an open task structure, which means that cognitive and executive functions must be maintained at an appropriate level during a fight. The aim of our study was to analyze the changes in ABB in capillary blood, measuring levels of H⁺, pCO₂, pO₂, HCO₃⁻, BE and total molar CO₂ concentration (TCO₂), which were recorded 3 and 20 min after a three-round kickboxing bout, and the level of technical and tactical skills presented during the fight. Methods: The study involved 14 kickboxers with the highest skill level (champion level). Statistical comparison of mentioned variables recorded prior to and after a bout was done with the use of Friedman’s ANOVA. Results: 3 min after a bout, H⁺ and pO₂ were higher by 41% and 11.9%, respectively, while pCO₂, HCO₃⁻, BE and TO₂ were lower by 14.5%, 39.4%, 45.4% and 34.4%, respectively. Furthermore, 20 min after the bout all variables tended to normalization and they did not differ significantly compared to the baseline values. Scores in activeness of the attack significantly correlated (r = 0.64) with pre–post changes in TCO₂. Conclusions: The disturbances in ABB and changes in blood oxygen and carbon dioxide saturation observed immediately after a bout indicate that anaerobic metabolism plays a large part in kickboxing fights. Anaerobic training should be included in strength and conditioning programs for kickboxers to prepare the athletes for the physiological requirements of sports combat.

Background: Series of whole-body cryotherapy (WBC) among healthy and physically active individuals can potentially reduce inflammatory response, although exact mechanisms remain unclear. Methods: The impact of whole-body cryotherapy on inflammation modulators among 28 young males, categorized as non-training (NTR, N = 10), non-training with WBC (NTR-WBC, N = 10), and training with WBC (TR-WBC, N = 8), is investigated in this study. Over a period of eight weeks, NTR-WBC and TR-WBC subjects underwent 24 WBC treatments (−130 °C for 3 min, three times a week), examining changes in mRNA expressions of IL-1A, IL-6, IL-10, IFN-G, SIRT1, SIRT3, SOD2, GSS, and ICAM-1. Results: The received data indicate an acute inflammatory response to initial WBC (increased IL-1A, IL-6, and SIRT), with a greater effect in NTR-WBC. Subsequent sessions showed enhanced expressions of antioxidative genes in both WBC groups, particularly non-trained, suggesting improved oxidative stress adaptation. A notable decrease in ICAM-1 mRNA post-24 WBC treatments in NTR-WBC signifies a potential systemic anti-inflammatory effect. Conclusions: The findings of the study suggest that the combination of regular physical activity with WBC administered three times per week can potentially modulate inflammatory and antioxidant responses. This modulation is evidenced by changes in the expression of genes related to these processes.

Maximal physical effort induces a disturbance in the body’s energy homeostasis and causes oxidative stress. The aim of the study was to determine whether prooxidant–antioxidant balance disturbances and the secretion of adipokines regulating metabolism, induced by maximal intensity exercise, are dependent on body composition in young, healthy, non-obese individuals. We determined changes in the concentration of advanced protein oxidation products (AOPP), markers of oxidative damage to nucleic acids (DNA/RNA/ox), and lipid peroxidation (LPO); catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activity, as well as concentrations of visfatin, leptin, resistin, adiponectin, asprosin, and irisin in the blood before and after maximal intensity exercise in men with above-average muscle mass (NFAT-HLBM), above-average fat mass (HFAT-NLBM), and with average body composition (NFAT-NLBM). We corrected the post-exercise results for the percentage change in plasma volume. In all groups after exercise, there was an increase in LPO and resistin. In HFAT-NLBM, additionally, an increase in CAT and a decrease in SOD activity were noted, and in NFAT-NLBM, an increase in visfatin concentration was observed. In our study, the effect was demonstrated of a maximal effort on six (LPO, CAT, SOD, visfatin, resistin, and asprosin) of the twelve parameters investigated, while the effect of body composition on all parameters investigated was insignificant. Maximal intensity aerobic exercise induces secretion of resistin and damages lipids regardless of the exercising subjects’ body composition. Large fat tissue content predisposes to exercise-induced disorders in the activity of antioxidant enzymes. We have also shown that it is necessary to consider changes in blood plasma volume in the assessment of post-exercise biochemical marker levels.