Hepatic ischemia-reperfusion injury (IRI) is a multifactorial phenomenon which has been associated with adverse clinical outcomes. IRI related tissue damage is characterized by various chronological events depending on the experimental model or clinical setting. Despite the fact that IRI research has been in the spotlight of scientific interest for over three decades with a significant and continuous increase in publication activity over the years and the large number of pharmacological and surgical therapeutic attempts introduced, not many of these strategies have made their way into everyday clinical practice. Furthermore, the pathomechanism of hepatic IRI has not been fully elucidated yet. In the complex process of the IRI, flow properties of blood are not neglectable. Hemorheological factors play an important role in determining tissue perfusion and orchestrating mechanical shear stress-dependent endothelial functions. Antioxidant and anti-inflammatory agents, ischemic conditioning protocols, dynamic organ preservation techniques may improve rheological properties of the post-reperfusion hepatic blood flow and target endothelial cells, exerting a potent protection against hepatic IRI. In this review paper we give a comprehensive overview of microcirculatory, rheological and molecular–pathophysiological aspects of hepatic circulation in the context of IRI and hepatoprotective approaches.

Hematocrit (Hct) is the major determinant of whole blood viscosity and of its oxygen binding capacity: with increasing Hct, viscosity increases exponentially and oxygen capacity increases linearly. Thus, the theoretical oxygen transport potential of

In surgical pathophysiology ischemia-reperfusion, inflammatory processes, sepsis, vascular interventions, tissue trauma, shock, all mean conditions in which hemorheological parameters show alterations. Despite of numerous clinical and experimental st

Although growing number of evidences supports the gender differences of hemorheological variables in human, little is known about this question in experimental animals. Investigating this question and giving laboratory-specific reference values, blood samples from healthy male and female CD rats and beagle dogs were tested for hematological parameters (microcell counter), blood and plasma viscosity (capillary viscometer), erythrocyte deformability (bulk filtrometry and ektacytometry), erythrocyte aggregation (light transmission aggregometer) and fibrinogen concentration (coagulometer). Besides the inter-species alterations we found hematological gender differences too regarding the red blood cell count and hematocrit. In rats the erythrocyte aggregation index was higher in females, while in beagle dogs the males showed significantly higher aggregation index values. In rats the red blood cell deformability showed better values in females. In beagle dogs this was the opposite, the males had better elongation index (EI) values in the function of shear stress (SS). Besides this it was also experienced that the shape of the canine EI – SS curves differed from the rats’ values. Gender differences with inter-species alterations can be observed in laboratory animals (rats and dogs) that have to be taken under consideration during planning experiments and evaluating results.

Acute pancreatitis still means a serious challenge in clinical practice. Its pathomechanism is complex and has yet to be fully elucidated. Rheological properties of blood play an important role in tissue perfusion and show non-specific changes in acute pancreatitis. An increase in blood and plasma viscosity, impairment of red blood cell deformability, and enhanced red blood cell aggregation caused by metabolic, inflammatory, free radical-related changes and mechanical stress contribute to the deterioration of the blood flow in the large vessels and also in the microcirculation. Revealing the significance of these changes in acute pancreatitis may better explain the pathogenesis and optimize the therapy. In this review, we give an overview of the role of impaired microcirculation by changes in hemorheological properties in acute pancreatitis.

BACKGROUND: Intestinal ischemia-reperfusion (I/R) is a potentially life-threatening situation and its pathomechanism is not fully understood yet. OBJECTIVE: To investigate the early micro-rheological, microcirculatory and morphological consequences of intestinal I/R in a rat model. METHODS: CD rats were anesthetized and subjected to Control ( n = 7) or I/R ( n = 7) groups. Left femoral artery cannulation and median laparotomy were performed. In the I/R group the superior mesenteric artery was clamped for 30 minutes. Blood samples were taken before (Base) and after the ischemia, at the 30th, 60th and 120th minutes of the reperfusion (R-30, R-60, R-120). Hematological parameters, erythrocyte deformability and aggregation were determined. On the jejunum, the liver and the right kidney laser Doppler flowmetry tests were completed. At the end of experiment histological samples were taken. RESULTS: Hematocrit, leukocyte and platelet counts increased during the reperfusion. Erythrocyte deformability worsened versus Control. All erythrocyte aggregation index values of I/R group increased gradually. Intestinal microcirculatory blood flux units (BFU) did not recover completely after ischemia, at R-30 liver BFU values were lower, and kidney values decreased by R-120. Histology showed signs of I/R injury. CONCLUSIONS: Micro-rheological parameters may show early and significant deterioration during the reperfusion that might contribute further to microcirculatory alterations.