Simultaneous investigation of hemodynamic, microcirculatory and arterio-venous micro-rheological parameters in infrarenal or suprarenal aortic cross-clamping model in the rat.

We aimed to investigate hemodynamic, microcirculatory and hemorheological consequence of infrarenal or suprarenal aortic cross-clamping (IRAXC, SRAXC) in the rat. We hypothesized that the magnitude of the changes are different. Twenty-one male rats were randomized into Control, IRAXC or SRAXC groups. Under anesthesia the right carotid artery was cannulated for monitoring heart rate and mean arterial pressure, then median laparotomy was performed. In AXC groups the abdominal aorta and the caudal caval vein were atraumatically clamped for 60 minutes below or above the renal vessels. Before and just after the ischemia, in the 30th and 60th minutes of the reperfusion besides hemodynamic test, laser Doppler flowmetry was used on the liver's, small-intestine's and the kidney's surface, then arterial (cannulated carotid artery) and venous (lateral tail vein) blood samples were taken for determining hematological, acid-base, erythrocytes' deformability, osmoscan and aggregation parameters. We found that when hemodynamic changes were prominent, microcirculatory or hemorheological parameters did not show such large differences. However, every parameter changed in various manners, showing more or less differences between IRAXC and SRAXC groups. Although the largest deviations were observable in SRAXC group, the acid-base and hemodynamic alterations were much more expressed than the micro-rheological ones. Further investigations of in vivo relations-correlations of changes in hemodynamic, microcirculatory, metabolic and hemorheological factors need further studies providing simultaneous monitoring possibilities.