The Expressions Of Vascular Endothelial Growth Factor (VEGF) In The Aggravating Course Of Microcirculation Of Pancreas

Objective: To establish the model of acute pancreatits aggravating from edema to necrosis in rats and to investigate the relationship between the expressions of vascular endothelial growth factor (VEGF) in serum and pancreas and the aggravating course of microcirculation in pancreas.Methods: Rats were randomly divided into three groups:sham normal group (N), acute edema pancreatits (AEP) and acute necrosis pancreatits (ANP). In 6h,12h and 24h after modeling, the serum VEGF,TNF-a and AMY were measured by ELISA, the expressions of VEGF protein in pancreas were detected by immunohistochemistry and the pancreas histology was detected by microscope.Results:1. The scores of VEGF protein in pancreas in AEP and ANP group by immunohistochemistry added in all time points compared with N group (P<0.05); The changes of the scores of VEGF protein in pancreas in AEP and ANP group by immunohistochemistry were not accordant completely, VEGF scores in AEP group increased persistently in all time points, while the scores decreased after 6h in ANP group, which were significantly different in all time points(P<0.05);VEGF scores in ANP group increased markedly in 6h, which were more distinct compared with AEP group(P＜0.05), yet the scores in ANP group reduced compared with AEP group in 12h and 24h(P<0.05).2. In 6h,12h and 24h after modeling, the serum VEGF,TNF-a and AMY in ANP and AEP group obviously increased, which were of significant difference compared with N group(P<0. 05); there was significant different between ANP and AEP group (P<0.05); but the VEGF expression in ANP and AEP group in 24h was of no significant difference (P> 0.05).3.The pathology of pancreas in AEP group were:The interstitium congestion and edema, neutrophils infiltration, diffuse necrosis of acinus, the changes of different time points were not evident; in ANP group, interstitium edema and haemorrhage, parenchyma focal necrosis, adiponecrosis, large erythrocytes sedimentation, some pancreatic ducts destruction and interstitium microvessels break were observed in 6h after modeling, the changes were more obvious in 12h and 24h, of which many erythrocytes overflowed, microvessel thrombosis and tissue autolyzed.Conclusions: the serum VEGF is associated with systemic inflammation response (SIRS); in edema pancreatits models, the VEGF immunohistochemistry scores are positive correlated with SIRS, while in models of aggravating pancreatic mi crocirculation, the VEGF immunohistochemistry scores are negative correlated with SIRS, demonstrating that the aggravating pancreatic microcirculation may cause severe injuries of pancreatic tissues and vascular endothelial cells, meanwhile accelerate the activating and releasing of various proteolytic enzymes, extensive thrombosis due to the abnormal mechanism of thrombus and hemostasia in microcirculation, indicating the pancreatic necrosis are hardly reversed.