Significance And Alteration Of Intermedin In Acute Pancreatitis Of Rats' Pancreas

Calcitonin/calcitonin gene-related peptide (CGRP), as a physiological and pathologicalmultiple functions regulator, is an important substance of the homeostatic regulatory functions inthe organism. Adrenomedullin (ADM) is an important substabce of endogenous protection,which can inhibit the production of pro-inflammatory cytokines, reduce ROS, endotoxin orcytokine-induced hyperpermeability in endothelial cells. Intermedin (IMD)is one of the newmembers of CGRP family. IMD has the same structure and functions with ADM, which isabound in heart, kidney, and lung. As a new endogenous protection, IMD has a better activitythan ADM. Studies have confirmed that ADM exists in the rat pancreas and has a significantprotective effect in acute pancreatitis (AP) rat pancreas, while there is no paper reported aboutIMD expression and mechanisms in the rat pancreas till now.Objective:the expression of IMD in the normal rat pancreas and in acute pancreatitis model wascompared and the protective effect of IMD in AP model was explored.Method:60 male Wistar rats were randomly divided into 6 groups: the L-Arg group (n=10) andthe control group (n=10), bombesin 6h group (C6h group) (n=10) and the control group (n=10),bombesin 24h group (C24h group) (n=10) and the control group. After rat model was completed,blood samples were collected from heart and the serum amylase level was detected by Elisa, andthe concentration of MDA was determined with TBA. The pathological changes weredetermined by HE stain, the edema degree was examined by the dry to wet weight radio. At last,the level of mRNA and IMD in pancreas was measured by RT-PCR and western blot,respectively.Results:Pathology results showed that lesions of C24h were most severe, followed by C6h groupand L-Arg group. The level of AMY: L-Arg group＞C24h group＞C6h group＞control group.Edema degree:C6h Group＞L-Arg group＞C24h group＞control group. MDA: C24h group＞C6hgroup＞L-Arg group＞control group. PT-PCR results indicated that the level of IMD mRNA ofC24h group was the lowest, followed by C6h group and L-Arg group. The level of IMD mRNAin the above three group were lower than the control groups.The sequence of western blot resultswas same as that of IMD mRNA results. IMD and IMD mRNA levels in pancreatic tissues weresignificantly negative relation to MDA (r= -0.72,r= -0.69, p<0.05).Conclusion:IMD wasexpressed both in the normal rat pancreas and in AP rat model. The more severe AP was, the lessIMD expressed. IMD is an important endogenous protective substance, involved in the pathogenesis of AP.