Thymosin alpha 1 improves severe acute pancreatitis in rats via regulation of peripheral T cell number and cytokine serum level

Aim: The aim of this study was to investigate the effect of thymosin alpha 1 (TA1) on severe acute pancreatitis (SAP) in rats. Methods: Healthy Sprague‐Dawley rats (n = 72) were randomly divided into four groups: control group, SAP group, and two TA1 treated groups. SAP was induced by injection of 5% sterile sodium taurocholate into the biliopancreatic duct (BPD), after which TA1 was given subcutaneously at 0 and 2 h at a dose of 100 μg/kg. The rats were killed at 3, 6 and 12 h, respectively. Serum amylase and lipase, interleukin (IL)‐1β, tumor necrosis factor‐alpha (TNF‐α), pancreatic wet/dry weight ratio and the percentage of CD3/CD4+/CD8+ T cells in peripheral blood mononuclear cells (PBMC) were measured. Next, 30 rats were randomly divided into three groups (each group containing 10 animals): SAP group (S) and two TA1 treated groups. The effects of TA1 on the survival of SAP were assessed 72 h after the induction of SAP. Results: There was no significant change in the serum amylase and lipase levels after TA1 administration. Levels of serum IL‐1β, TNF‐α and pancreatic wet/dry weight ratio were significantly reduced after TA1‐treatment. Application of TA1 significantly balanced CD3/CD4+/CD8+ T cells of PBMC and improved histological scores and the survival rate. Conclusion: TA1 can reduce pancreatic inflammation by regulating differentiation of CD3/CD4+ T cells and decreasing the release of cytokines, thus attenuates pancreatic severity in SAP rats.