Changes of blood IL-6, TNF-α and effects of low dose dopamine in rats with severe acute pancreatitis

Abstract

Objective To study the changes of blood IL-6, TNF-α and evaluate the therapeutic mechanism of low dose dopamine in severe acute pancreatitis （SAP）. Methods Sixty Wistar rats were divided in- to 3 groups： false operation group （group I）, dopamine treatment group （group Ⅱ） and SAP control group （ group Ⅲ ）. An animal model of acute pancreatitis was established by injecting sodium taurocholate into the pancreatic duct. The operation of Group Ⅰ （ n = 20） was only opened abdomen. Group Ⅱ （ n = 20） ： 5 ug. kg^-1· min^-1 was dopamine given intravenously while for control one （n = 20）, normal saline was given. Blood samples were taken from the jugular vein before the experiment and at 2,4,6,12 hours after the experiment. The IL-6 and TNF-α were detected by ELISA technique. The pancreas was examined histologically 12 hours after the treatment. Results The serum levels of IL-6 and TNF-α were similar before operation （ t = 0.64, 1.38,P 〉0.05） ,but the levels were higher after operation. The levels of IL-6 and TNF-α of the dopamine treatment group were lower than that of the SAP control one ,the difference was significant （t = 6.23-32.32, P 〈 0.01 ）. The grade of pancreatic histopathology of dopamine group was obviously lower than that of the SAP group （ t = 3.92 - 9.94, P 〈 0.01 ）. Conclusions The cytokines （ TNF-α, IL-6 ） play an important role in the development of acute pancreatitis. While low - dose dopamine may reduce the inflammatory reaction of acute pancreatitis, perhaps because low dose of dopamine not only increases the blood flow of pancreatic microvessel but also reduces its permeability. Key words: severe acute pancreatitis; dopamine; interleukin-6; tumor necrosis factor-α