The Effect Of Apelin-13 On Autophagy In Pancreatic Tissue Of Rats With Acute Necrotizing Pancreatitis

Objective:To study the effect of apelin-13 on autophagy in pancreatic tissue of rats with acute necrotizing pancreatitis,and explore the relationship between apelin-13 and autophaly in ANP. Methods:54 male Sprague-Dawley rats were average divided into three groups randomly: group C(Control group), group P(NAP group) and group S(ANP+ apelin-13group),and 18 rats in each group Group C was sham operated group.The ANP models were induced by retrograde injection of 5% sodium taurocholate intobilopancreatic duct of SD rats.S group given Apelin-13 intravenous injection intervention 5min after model establishment of acute pancreatitis. P and S groups were pretreated with an injection of saline and apelin-13(0.1ug/g)into the rats via tail vein 5min after establish a model of acute necrotizing pancreatitis.Each group of rats were blooded from the abdominal aorta, in the 3h,6h,12 h after anesthesia,and testing serum levels of amylase;and some were used do 4% formalin-fixed, regular sections, HE staining; In the other part,the expression of autophagy related protein LC3-II and Beclin-1 was detected by Western-Blot. Results: 1. Pancreatic pathology score:(1)There is a significant difference between C group and P group, S group at the same time point(P<0.05);(2)P group injury score were significantly increased. And the degree of injury increases over time, meanwhile, significant difference exist between each point in time(P<0.05).(3)The pathological damage score of S group than in P group at each time point has been reduced(P<0.05).2.Serum amylase:(1) There isn't any significant differences between each point in time in C group.(2) Serum amylase in P group was significantly higher than C group(control group) At each time point(P<0.05).Compared with P group, serum amylase in S rats at each time point were significantly reduced(P<0.05).3. The results of Western-Blot detection of LC3- II, Beclin1 expression.Compared with C group, ANP in 3h, 6h,12 h rats, P group of autophagy related protein LC3-II, Beclin-1 protein expression was significantly up-regulated(P<0.05). However, compared with the P group, The expression level of S group at each time point can be down regulated autophagy related protein LC3-II and Beclin-1 protein. Conclusion:1. The expression of autophagy is increased in Sprague-Dawley rats with acute necrotizing pancreatitis,the expression of autophagy increased with the degree of pathological damage.2. Apelin-13 suppresses autophagy in NAP possibly by down-regulating protein Beclin-1, LC3- II ratio.