早期大剂量维生素C对重症急性胰腺炎大鼠核因子-κB的影响

The effect of early used high-dose vitamin C on NF-κB of rats with serious acute pancreatitis

目的:观察早期大剂量应用抗坏血酸(维生素C)对重症急性胰腺炎(SAP)大鼠的核因子-!B(NF-!B)的影响,研究其作用机制。方法:将72只SAP模型SD大鼠随机分成3组,每组各24只。A组:由大鼠股静脉滴注生理盐水5 ml/kg。B组:大鼠股静脉滴注Vit C 15 mg/kg加生理盐水至5 ml/kg。C组:由大鼠股静脉滴注Vit C 150 mg/kg加生理盐水至5 ml/kg。另取8只SD大鼠作为正常对照组。各组分别于8 h和24 h处死8只大鼠,采血测淀粉酶、脂肪酶、维生素C(PV-C)、超氧化物歧化酶(SOD)、TNF-αI、L-6。大鼠处死时分别取胰头组织3份,一份组织HE染色,行光镜检查,按Kusske的方法,对水肿、炎症、出血和坏死分别评分;一份制成超薄切片,行电镜检查;另一份SP法进行免疫组化染色,检测NF-!B的表达。每组另外8只大鼠观察3 d内存活情况,计算3 d成活率。结果:各组大鼠3 d内的生存率为正常对照组100%(8/8),A组0%(0/8),B组12.5%(1/8),C组50%(4/8),C组的3 d生存率显著高于其他两组(P<0.05)。各组的4项病理学评分均高于正常对照组(P<0.01),C组的4项病理学评分均低于A、B组(P<0.05)。透射电镜检查示C组中分泌颗粒较少,其包膜完整、内质网轻度肿胀、线粒体清晰,未见大片坏死。SAP大鼠体内淀粉酶、脂肪酶、细胞因子TNF-α和IL-6的水平明显增高,血清SOD和P-VC降低,胰腺组织中NF-!B活化阳性胰腺细胞数明显增多。C组的血清淀粉酶和脂肪酶低于A、B组(P<0.05),SOD和P-VC水平高于A、B组(P<0.05),血清TNF-αI、L-6水平低于A、B组(P<0.05),胰腺组织NF-!B活化水平低于A、B组(P<0.05)。结论:早期大剂量应用Vit C有助于及时提高SAP大鼠的P-VC、E-SOD水平,降低体内淀粉酶、脂肪酶、TNF-αI、L-6水平,其作用机制可能与大剂量Vit C抑制SAP大鼠体内NF-!B活化、在整体水平上抑制细胞因子基因表达、有助于机体免受自由基和过量细胞因子的损伤及减轻胰腺组织的病理性改变等因素有关。

Objective To ohserve the effect of early application oi high-dose vitanlin C on NF-κB ot rats with serious acute pancreatitis and to study its mechanism. Methods A total of 72 SAP rats were equally divided into 3 groups, and 8 beahhy rats were taken as nomtal controls. Group A： given NS （5 ml/kg） through vein; Group B： given NS （5 ml/kg） and vitamin C（15 ml/kg） intravenously： Group C： given NS （5 ml/kg） and vitamin C （150 mg/kg） intravenously. Eight and 24 hours after induction of rats, 8 rats of each group were sacrificed and hlood samples were taken for the measurement of serum amylase, lipase, SOD, PV-C, TNF-α and IL-6. Pathological study and NF-κB aetivity in the pancreas were detected hv immuno-histochemieai melhods. The survival rate in 3 days of other 8 rats of each group was observed, Results The survival rate of each group was 100%（8/8） in normal group. 0%（0/8） in Group A, 12.5 %（1/8） in Group B, and 50 %（4/8） in Group C, The pathological seores of the pancreas were much higher in SAP rats than that in the normal group, The survival pathological scores and the activity of NF-κB of the pancreas were lower in Group C than that in Groups A and B. The serum level of amylase, lipase, TNF-α and IL-6 were much higher in SAP rats than that in the normal group and lower in Group C than that in Groups A and B. The serum level of SOD and PV-C were lower in SAP rats than that in the nor- real group, while much higher in Group C than that in Groups A and B. Conclusions Early usage of high-dose vitamin C for the treatment of SAP rats is effective in raising the level of SOD and PV-C, and in inhibiting the activity of NF-κB. The inhibition of the activity of NF-κB might be a promising strategy in treating SAP by down-regulating the free radicals and cytokines in the body.