Aorto-porto-caval micro-rheological differences of red blood cells in laboratory rats: Further deformability and ektacytometrial osmoscan data

Abstract

Investigation of regional hemorheological properties are important in ischemia-reperfusion experimental surgical and microsurgical research models, however, the physiological arterio-venous as well as porto-caval differences in erythrocyte deformability and aggregation are still controversial. In this study, besides measuring blood pH, blood gases, lactate concentration and hematological parameters we determined erythrocyte deformability (rotational ektacytometer) together with osmoscan data as well as erythrocyte aggregation (light transmittance aggregometer) in blood samples taken from the portal vein, caudal caval vein and abdominal aorta of rats. Blood pH, partial blood gas pressures showed the anticipated physiological differences. Leukocyte count was lower in arterial blood; hematocrit, erythrocyte and platelet count was higher in systemic and portal venous blood. The lowest elongation index values were measured in arterial blood, the highest in venous and portal venous blood showed values in between. The osmoscan data did not show important differences. Erythrocyte aggregation M index 5 s showed the lowest values in arterial, higher in systemic venous and portal venous blood samples. M index 10 s showed significantly low values in systemic venous blood. M1 values were slightly higher in arterial blood compared to venous blood but the highest were in portal venous blood. Erythrocyte deformability and aggregation may show aorto-porto-caval differences in the rat. The appropriate control examinations thus are important in experimental surgical and microsurgical research models.

Influence of stent implantation on erythrocyte aggregation in human native coronary arteries and saphenous vein grafts

“… Shear and tensile stress: In vivo, blood flow and shear/tensile stress and in consequence RBC aggregation differ between arteries and veins. Different oxygen saturation of arterial and venous blood also impacts on RBC aggregation in animal models, but not in humans . Acute disruption of blood flow, for example, by a distal balloon occlusion device, as done in the present study, changes both shear/tensile stress and oxygen saturation.…”

Hemorheological and Microcirculatory Factors in Liver Ischemia-Reperfusion Injury—An Update on Pathophysiology, Molecular Mechanisms and Protective Strategies

“…There is only limited information about the characteristics of micro-rheological parameters in different vascular segments [26,67]. It has been demonstrated that red blood cell aggregation and deformability show significant aorto-porto-caval differences in rats [68]. The smallest elongation index values were found in the arterial samples, the highest values were in the systemic venous blood and the values of the portal blood sample fall between the two.…”

“…These differences could not be observed in human or in canine blood [67]. The aggregation index parameters are significantly lower in the systemic venous blood, than in the arterial and portal samples [68]. The explanation of these arterio-venous or porta-caval micro-rheological heterogeneity might be derived from the dynamic differences in pH, oxygenation level, lactate concentration, hematocrit and mean cell volume [22,23,26,40,69].…”