Does nitric oxide protect from microcirculatory disturbances in experimental acute pancreatitis in rats?

The aim of the study was to investigate the potential role of nitric oxide (NO) on the microcirculation in experimental acute pancreatitis in rats. Twenty-five rats were divided into the following groups: group A (5 rats) = control; group B (5 rats)= acute pancreatitis induced by retrograde taurocholate infusion into the pancreatobiliary duct without treatment; group C (5 rats) = acute pancreatitis treated with the NO donor L-arginine; group D (5 rats) = acute pancreatitis treated with the NO synthase inhibitor N-nitro-L-arginine (L-NNA); group E (5 rats) = without pancreatitis receiving L-NNA. The animals were observed throughout 4 h. The microcirculatory values of the pancreas, liver, colon, stomach and kidney were measured by means of laser Doppler flowmetry. Three animals of group D died after the third hour of the experiment. In rats with pancreatitis, a rapid decrease in microcirculatory values was observed. The most pronounced drop in capillary blood flow within all the organs was observed in rats treated with the NO synthase inhibitor L-NNA, L-arginine administration in rats with acute pancreatitis slightly improved the microcirculatory values, although the improvement was significant in colon perfusion only. We conclude that NO may have a beneficial influence on the capillary organ perfusion in acute pancreatitis. The administration of an NO synthase inhibitor seems to have a detrimental effect on acute pancreatitis.