Pancreatic microcirculatory impairment in experimental acute pancreatitis in rats

Abstract

Aim: To study the feature of pancreatic microcirculatory impairment, especially the initial changes, in caerulein-induced experimental acute pancreatitis (AP).

Methods: The pancreatic microcirculation of caerulein-induced AP model was studied by intravital fluorescence microscopy with FITC-labeled erythrocytes (FITC-RBC), scanning electron microscopy of vascular corrosion casts, and light microscopy of Chinese ink-injected/cleared tissues.

Results: Animals in caerulein-treated group showed hyperamylemia (X2), pancreatic oedema, infiltration of inflammatory cells in pancreas. Constrictions of intralobular arteriolar sphincters, presence of vacuoles in all layers of sphincter, and gross irregularity in capillary network of acini were found in the AP specimens. The decrease of pancreatic capillary blood flow (0.34+/-0.10 nl x min(-1) vs 0.91+/-0.06 nl x min(-1) of control, P<0.001), reduction of functional capillary density(277+/-13 cm(-1) vs 349+/-8 cm(-1) of control, P<0.001), and irregular intermittent perfusion were observed in caerulein-induced groups.

Conclusion: Impairment and constriction of pancreatic intralobular arteriolar sphincter are the initial microcirculatory lesions in the early phase of acute pancreatitis, and play a key role in the pancreatic ischaemia and pancreatic microvascular failure in acute pancreatitis.