Simultaneous investigation of hemodynamic , 1 microcirculatory and arterio - venous 2 micro - rheological parameters in inf arenal 3 or suprarenal aortic cross - clamping model

We aimed to investigate hemodynamic, microcirculatory and hemorheological consequence of infrarenal or suprarenal 10 aortic cross-clamping (IRAXC, SRAXC) in the rat. We hypothesized that the magnitude of the changes are different. Twenty-one 11 male rats were randomized into Control, IRAXC or SRAXC groups. Under anesthesia the right carotid artery was cannulated 12 for monitoring heart rate and mean arterial pressure, then median laparotomy was performed. In AXC groups the abdominal 13 aorta and the caudal caval vein were atraumatically clamped for 60 minutes below or above the renal vessels. Before and just 14 after the ischemia, in the 30th and 60th minutes of the reperfusion besides hemodynamic test, laser Doppler flowmetry was used 15 on the liver’s, small-intestine’s and the kidney’s surface, then arterial (cannulated carotid artery) and venous (lateral tail vein) 16 blood samples were taken for determining hematological, acid-base, erythrocytes’ deformability, osmoscan and aggregation 17 parameters. We found that when hemodynamic changes were prominent, microcirculatory or hemorheological parameters did 18 not show such large differences. However, every parameter changed in various manners, showing more or less differences between 19 IRAXC and SRAXC groups. Although the largest deviations were observable in SRAXC group, the acid-base and hemodynamic 20 alterations were much more expressed than the micro-rheological ones. Further investigations of in vivo relations-correlations of 21 changes in hemodynamic, microcirculatory, metabolic and hemorheological factors need further studies providing simultaneous 22 monitoring possibilities. 23