Analysis of the derangement of the pancreatic microcirculation in a rat caerulein pancreatitis model using an intravital microscope system.

In order to clarify the derangement of the pancreatic microcirculation in acute pancreatitis, the pancreatic microcirculation in caerulein pancreatitis was monitored intravitally and the roles of bradykinin and nitric oxide were examined using bradkykinin B2 receptor antagonist, HOE140. Under an intravital microscope, the pancreatic microcirculation was observed 2 or 6 hr after the induction of acute pancreatitis. HOE140 was administered 30 min before the induction of acute pancreatitis. The videoimages were taken into the computer, and the value of grayscale was measured with imaging software to quantify the degree of extravasation. Extravasation in the postcapillary venules was remarkable and the velocity in pancreatic terminal arterioles decreased significantly. However, the adherence of leukocytes was not observed until 6 hr after the induction. Both the extension of extravasation and the decrease of velocity were prevented by HOE140. The levels of nitric oxides in the pancreatic tissue declined and this decline was not influenced by HOE140. Bradykinin participates mainly in the regulation of vascular permeability in the early stage of caerulein pancreatitis. Further, the impairment of pancreatic microcirculation may play a key role in the onset and development of acute pancreatitis.