胸腺素β4对重症急性胰腺炎大鼠的保护作用

Protective effect of thymosin β4 on severe acute pancreatitis in rats

目的 探讨胸腺素β4腹腔注射给药对重症性胰腺炎大鼠的保护作用及机制.方法 雄性SD大鼠54只,随机（随机数字法）分为3组：假手术组（SO组）、重症急性胰腺炎组（SAP组）、胸腺素β4预处理组（Tβ4组）,每组18只.采用5％牛磺胆酸钠逆行胆胰管注射制备大鼠SAP模型,Tβ4组在造模前30 min经腹腔注射胸腺素β4（6 mg/kg）,术后3、6、12h分批剖杀大鼠,各时间点6只.检测血清淀粉酶、TNF-α、IL-1β及IL-6水平,光镜观察胰头部组织病理变化,Western blot检测胰腺组织NF-κB p65和IκB α蛋白表达水平.多个样本均数比较采用单因素方差分析,两组间比较采用t检验.结果 SAP组（3、6、12 h）血清淀粉酶分别为（3221 ±394） U/L、（4509±474） U/L和（6280±728） U/L,高于相应时间点Tβ4组的（2598±416） U/L、（3639±373） U/L和（4782±466） U/L,差异具有统计学意义（t=-2.666,-3.530,-4.245,P＜0.05）;SAP组（3、6、12 h）TNF-α分别为（247.7±18.5） pg/mL、（313.5±17.7） pg/mL和（359.3±22.6）pg/mL,均高于Tβ4组相应时间点的（182.3 ±13.6） pg/mL、（258.9±14.9）pg/mL和（278.1±16.3）pg/mL,差异具有统计学意义（t=-6.964,-5.769,-7.152,P＜0.05）;SAP组（3、6、12 h）IL-1β分别为（258.2±10.5） pg/mL、（345.1±22.0） pg/mL和（430.9±25.4） pg/mL,均高于Tβ4组相应时间点的（170.3±12.4） pg/mL、（263.5±13.3） pg/mL和（303.7±16.1）pg/mL,差异具有统计学意义（t=-13.258,-7.762,-10.355,P＜0.05）;SAP组（3、6、12 h）IL-6分别为（266.3±11.5） pg/mL、（355.0±24.4） pg/mL和（429.2±33.7） pg/mL,均高于Tβ4组相应时间点的（171.1±13.0） pg/mL、（234.9±19.2） pg/mL和（277.2±19.2）pg/mL,差异具有统计学意义（t=-13.401,-9.474,-9.582,P＜0.05）;SAP组（3、6、12 h）胰腺病理评分分别为（6.25±0.94）分、（8.83 ±0.82）分和（12.08±1.16）分,显著高于Tβ4组相应时间点的（4.17±0.93）分、（6.33 ±0.82）分和（7.33±1.25）分,差异具有统计学意义（t=-3.867,-5.303,-6.823,P＜0.05）.SO （12 h）组胰腺组织NF-κBp65蛋白相对表达量为0.95 ±0.11,显著低于SAP（12 h）组的（2.40±0.17）,差异具有统计学意义（t=-17.368,P＜0.05）,Tβ4组胰腺组织NF-κB p65蛋白相对表达量为（1.50 ±0.10）,较SAP （12 h）组显著降低,差异具有统计学意义（t=10.917,P＜0.05）.SO （12h）组胰腺组织IκB α蛋白相对表达量为（1.93±0.11）,显著高于SAP （12 h）组的（0.78±0.18）,差异具有统计学意义（t=13.260,P＜0.05）,而Tβ4 （12 h）组胰腺组织IκB α蛋白相对表达量为（1.12±0.10）,较SAP （12 h）组显著升高,差异具有统计学意义（t=4.112,P＜0.05）.结论 胸腺素β4对重症急性胰腺炎大鼠具有保护作用.其作用机制可能与抑制胰腺NF-κB信号通路的活化及降低炎症细胞因子的水平有关.

Objective To investigate the protective effects and mechanisms of intraperitoneal administration of thymosin β4 on severe acute pancreatitis in rats.Methods Fifty-four male Sprague-Dawley rats were randomly （random number） divided into sham operation （SO） group,severe acute pancreatitis （SAP） group and thymosin β4 （Tβ4） pretreatment group （n =18 in each group）.SAP rat model was prepared by retrograde injection of 5％ sodium taurocholate into the biliopancreatic duct.Rats in Tβ4 group were treated with thymosin β4 （6 mg/kg） by intraperitoneal administration prior to SAP modeling.Six rats in each group were sacrificed at 3,6,12 hours,respectively after modeling.The serum levels of amylase,tumor necrosis factor-α （TNF-α）,interleukin-1 β （IL-1 β）,and interleukin-6 （IL-6）were detected,and pathological scores of the tissue of pancreas head were evaluated under light microscope.Pancreatic nuclear factor-kappa 1B （NF-κB） p65 and IκB α levels were detected by the Western blot.All data were analyzed by using the analysis of variauce or t test.Results The levels of serum amylase of SAP 3,6 and 12 hours groups were （3221 ±394） U/L,（4509 ±474） U/L and （6280 ±728） U/L,which were significantly higher than （2598±416） U/L,（3639 ±373） U/L and （4782 ±466） U/L of the Tβ4 groups （t =-2.666,-3.530,-4.245,P ＜ 0.05）.The levels of serum TNF-α of the SAP 3,6 and 12 hours groups were （247.7 ± 18.5） pg/mL,（313.5 ± 17.7） pg/mL and （359.3 ±22.6） pg/mL,which were higher than （182.3 ± 13.6） pg/mL,（258.9 ± 14.9） pg/mL and （278.1 ± 16.3） pg/mL of the Tβ4 groups （t =-6.964,-5.769,-7.152,P ＜ 0.05）.The levels of serum IL-1 β of the SAP 3,6 and 12 hours groups were （258.2±10.5） pg/mL,（345.1 ±22.0） pg/mL and （430.9 ±25.4） pg/mL,which were higher than （170.3 ± 12.4） pg/mL,（263.5 ± 13.3） pg/mL and （303.7 ± 16.1） pg/mL of the Tβ4 groups （t =-13.258,-7.762,-10.355,P ＜ 0.05）.The levels of serum IL-6 of SAP 3,6 and 12 hours groups were （266.3 ±11.5） pg/mL,（355.0 ±24.4） pg/mL and （429.2 ±33.7） pg/ mL,which were higher than （171.1 ± 13.0） pg/mL,（234.9 ± 19.2） pg/mL and （277.2 ± 19.2） pg/ mL of the Tβ4 groups （t =-13.401,-9.474,-9.582,P ＜ 0.05）.The pancreatic pathological scores of the SAP3,6 and 12 hours groups were （6.25 ±0.94）,（8.83 ±0.82） and （12.08 ±1.16）,which were higher than （4.17 ± 0.93）,（6.33 ± 0.82） and （7.33 ± 1.25） of the Tβ4 groups （t =-3.867,-5.303,-6.823,P ＜ 0.05）.The relative expression of pancreatic NF-κB p65 in SO group was （0.95 ±0.11）,which was significantly lower than （2.40 ±0.17） of the SAP 12 hours group （t =-17.368,P＜ 0.05）.The relative expression of pancreatic NF-κB p65 in Tβ4 group was 1.50 ± 0.10,which was significantly lower than SAP 12 hours group （t =10.917,P ＜0.05）.The relative expression of pancreatic IκB α in SO group was （1.93 ±0.11）,which was significantly higher than （0.78 ±0.18） of the SAP 12 hours group （t =13.260,P ＜ 0.05）.The relative expression of pancreatic IκB α in Tβ4 group was （1.12±0.10）,which was significantly higher than SAP 12 hours group （t =-4.112,P ＜ 0.05）.Conclusions Thymosin β4 has the protective effect on SAP rat model,and the mechanism may be associated with inhibition of NF-κB signaling pathway and decreased proinflammatory cytokines.