Plasma and blood osmolality values show interspecies differences and are strictly regulated. The effect of these factors also has an influence on microrheological parameters, such as red blood cell (RBC) deformability and aggregation. However, little is known about the interspecies differences in RBC deformability at various blood osmolality levels (osmotic gradient RBC deformability). Our aim was to conduct a descriptive–comparative study on RBC osmotic gradient deformability in several vertebrate species and human blood. Blood samples were taken from healthy volunteers, dogs, cats, pigs, sheep, rabbits, rats, and mice, to measure hematological parameters, as well as conventional and osmotic gradient RBC deformability. Analyzing the elongation index (EI)–osmolality curves, we found the highest maximal EI values (EI max) in human, dog, and rabbit samples. The lowest EI max values were seen in sheep and cat samples, in addition to a characteristic leftward shift of the elongation index–osmolality curves. We found significant differences in the hyperosmolar region. A correlation of mean corpuscular volume and mean corpuscular hemoglobin concentration with osmoscan parameters was found. Osmotic gradient deformability provides further information for better exploration of microrheological diversity between species and may help to better understand the alterations caused by osmolality changes in various disorders.

Optimal tissue oxygen supply is essential for proper athletic performance and endurance. It also depends on perfusion, so on hemorheological properties and microcirculation. Regular exercise is beneficial to the rheological status, depending on its type, intensity, and duration. We aimed to investigate macro and microrheological changes due to short, high-intensity exercise in professional athletes (soccer and ice hockey players) and untrained individuals. The exercise was performed on a treadmill ergometer during a spiroergometry examination. Blood samples were taken before and after exercise to analyze lactate concentration, hematological parameters, blood and plasma viscosity, and red blood cell (RBC) deformability and aggregation. Leukocyte, RBC and platelet counts, and blood viscosity increased with exercise, by the largest magnitude in the untrained group. RBC deformability slightly impaired after exercise, but showed better values in ice hockey versus soccer players. RBC aggregation increased with exercise, dominantly in ice hockey players. Lactate increased mostly in soccer players, and the respiratory exchange rate was the lowest in ice hockey players. Overall, short, high-intensity exercise altered macro and microrheological parameters, mostly in the untrained group. Significant differences were found between the two sports. The data can be useful in training status monitoring, selection, and in revealing the causes of physical loading symptoms.

Polycystic ovary syndrome (PCOS) is one of the most common endocrinological diseases in women. Although the risk of cardiovascular diseases is high in PCOS, the number of scientific publications describing hemorheological changes is not significant. We aimed to perform a comprehensive hematological and micro-rheological study on experimentally induced PCOS in rats.Wistar rats were divided into control (n = 9) and PCOS groups (n = 9), in which animals received single-dose estradiol valerate. Measurements were carried out before treatment and monthly for four months. Bodyweight, blood glucose concentration, hematological parameters, red blood cell (RBC) deformability, and aggregation were measured. A histological examination of the ovary was performed at the end of the experiment. The blood glucose level and the bodyweight were significantly elevated vs. base in the PCOS group. A significant decrease was seen in RBC count, hemoglobin, and hematocrit. The maximal elongation index showed a significant increase. PCOS also resulted in a significant increase in RBC aggregation index parameters. The histological and hormone examinations confirmed developed PCOS. The administration of estradiol valerate caused significant changes during the examined period in hematological and hemorheological parameters. Our results draw attention to the possible usefulness of micro-rheological investigations in further studies on PCOS.

Ischemia–reperfusion (I/R) strongly affects a graft’s function and survival and modulates microcirculatory and hemorheological parameters. However, the boundary between the reversibility and irreversibility of damage is unclear. This study compared the effects of renal I/R and ischemic preconditioning (IPC) to determine whether metabolic, microcirculatory, and micro-rheological changes are already detectable in the first hour of reperfusion. Wistar rats were divided into control (n = 6), I/R (n = 7) and IPC (n = 7) groups. In the ischemic groups the left kidney was subjected to 120 min of ischemia followed by 60 min of reperfusion. In the IPC group, a 3 × 5 min protocol was used prior to the manifest ischemia. Parenchymal microcirculation and renal artery blood flow were measured before ischemia (base) and during reperfusion (R-30, R-60). Hematological, micro-rheological parameters, electrolytes, and metabolites were tested at base and at R-60. Both ischemic groups showed micro-rheological impairment. An increase in potassium, lactate, and creatinine concentrations and a decrease in pH were observed. The blood flow of the IPC group deteriorated less, and microcirculation recordings indicated better values. The 120 min ischemia and the 60 min reperfusion resulted in micro-rheological and metabolic alterations, together with decreased renal blood flow and parenchymal microcirculation. Although the applied IPC protocol showed minor protective effects, its impact was limited in the first hour of reperfusion.

Physical activity influences red blood cell (RBC) deformability and aggregation, which affect oxygen transport and performance. While regular training may enhance RBC properties, adaptations depend on exercise intensity, duration, and recovery. This study aimed to assess the impact of a 12-week core muscle training program on RBC deformability, aggregation, and aerobic capacity in military trainees. A total of 35 male volunteers were divided into a Training group (n = 17) and a Control group (n = 18). The intervention included dynamic stretching, core stabilization, and functional movement exercises. Spiroergometry tests, blood gas analysis, and hemorheological measurements were conducted before and after the program. Results showed no significant changes in body composition or aerobic capacity. RBC deformability slightly decreased after exercise in both groups, while RBC aggregation increased. Blood viscosity changes were more moderate in the Training group, suggesting potential adaptation. However, the training intensity may have been insufficient for significant hemorheological improvements. While regular physical activity can enhance RBC function, adequate intensity, recovery, and nutrition are essential for optimal adaptation. Individualized training strategies should consider these factors to maximize performance and hemorheological benefits.

Hemorheological factors may show arterio-venous differences. Alterations in acid-base and metabolic parameters may also influence these factors. However, little is known about changes in micro-rheological parameters during abdominal surgery, influencing splanchnic circulation. In anesthetized pigs, the external jugular vein, femoral artery and vein were cannulated unilaterally, and paramedian laparotomy was performed. In the anastomosis group, after resecting a bowel segment, end-to-end jejuno-jejunostomy was completed. Blood samples (from cannulas and by puncturing the portal vein) were taken before and after the intervention. Hematological, acid-base and blood gas parameters, metabolites, red blood cell (RBC) deformability and aggregation were determined. The highest hematocrit was found in portal blood, increasing further by the end of operation. A significant pH decrease was seen, and portal blood showed the highest lactate and creatinine concentration. The highest RBC aggregation values were found in arterial, the lowest in renal venous blood. The RBC aggregation increased with higher lactate concentration and lower pH. Osmotic gradient deformability declined, with the lowest values in portal and renal venous samples. In conclusion, micro-rheological parameters showed arterio-venous and porto-renal venous differences, influenced by oxygenation level, pH and lactate concentration. The intestinal anastomosis operation caused an immediate micro-rheological deterioration with portal venous dominancy in this experiment.