抗氧化剂对慢性胰腺炎大鼠胰腺纤维化的影响

Effect of antioxidants on pancreatic fibrosis of rats with chronic pancreatitis

目的观察外源性给予四氢吡咯二硫代氨基甲酸盐（PDTC）等氧化剂对慢性胰腺炎（CP）大鼠胰腺纤维化的影响，并探讨其机制。方法按完全随机法将大鼠分为对照组、CP组、PDTC治疗组、维生素E（VitE）治疗组、维生素C（VitC）治疗组。采用腹腔内注射二乙基二硫代氨基甲酸盐（DETC）750mg／kg体质量、每周2次的方法制备cP模型。对照组不做任何处理。各治疗组在注射DETC后30min腹腔内分别注射PDTC100m/kg体质量、VitE15m/kg体质量、Vit C15mg／kg体质量。注射DETC后90min，24、48、72h，2、3、4、6周时分批处死大鼠。取胰腺组织行常规病理检查，采用分光光度比值法检测胰腺组织超氧化物歧化酶（SOD）、丙二醛（GSH—PX）和谷胱甘肽过氧化物酶（MDA）活性，免疫组化法检测α-平滑肌肌动蛋白（α-SMA）、结蛋白（Desmin）、胶原I及Ⅲ、TGF-β1、纤维连接蛋白（FN）蛋白表达，RT—PCR法检测TGF—B1mRNA、FNmRNA表达。结果各治疗组6周时胰腺纤维化指标和腺体破坏指标都明显低于CP组（P值均〈0．01），VitC组和VitE组空泡样变指数也小于CP组（P值均〈0．01）。2周起PDTC组、VitC组和VitE组胰腺的SOD、GSH—PX活性均较同时间点CP组升高，而MDA含量较同时间点CP组下降，差异均有统计学意义（P〈0．05或〈0．01），各治疗组间的差异无统计学意义。2周后各治疗组TGF．B1、FNmRNA水平均较cP组下降（P〈0．05或〈0．01），但仍高于对照组（P值均〈0．05），各治疗组间的差异无统计学意义。结论PDTC等抗氧化剂通过增强SOD等活性减少氧自由基产生，抑制PSCs的活化，并通过降低TGF—B1分泌，减少胶原I、胶原m、FN的产生，抑制胰腺的纤维化。

Objective To investigate the effect of antioxidants including PDTC on pancreatic fibrosis of rats with chronic pancreatitis. Methods The rats were randomly divided into 5 groups including control group, CP group, PDTC treatment group, vitamin E treatment group and vitamin C treatment group. The CP model was in duead by using intraperitoneal injection of DETC （750 mg/kg）, twice a week. The control group received no treatment. After DETC injection, the treatment groups received an intraperitoneal injection of PDTC （ 100 mg/kg） , vitamin E （ 15 mg/kg） , vitamin C （ 15 mg/kg） , respectively. Rats were sacrificed at 90 rain, 24 h, 48 h, 72 h, 2 w, 3 w, 4 w, 6 w after first injection of DETC. Pancreatic tissue was taken for routine pathological examination. The activity of SOD, GSH-PX and MDA content were detected by spectrophotometric ratio method. α-SMA, desmin collagen I, III, TGF-131, FN were detected by immunohistochemical assay. The expression of TGF-β1, FN mRNA was measured by RT-PCR. Results At 6w, the fibrosis and the parameters for damage of the pancreas in the three treatment groups were significantly better than that in CP group （ P 〈 0.01 ）, the vacuolar degeneration index in vitamin E group and vitamin C group was also better than that in CP group （P 〈 0.01 ）. From the 2nd week, the activity of SOD, GSH PX in PDTC group, Vit C group and Vit E group was higher than that in CP group, while the MDA activity was lower than that in CP group, and the difference was statistically significant （P 〈 0.01 or P 〈 0.05 ）. No significant difference was found among the three treatment groups. The mRNA levels of TGF-I31 and FN of the treatment groups were lower than those of CP group （P 〈0.05 or P 〈0.01 ）, but higher than those of the control group （P 〈 0.05）. There was no significant difference among the three treatment groups （ P 〉 0.05 ）. Conclusions PDTC and the other antioxidants can reduce oxygen free radicals by increasing the activity of SOD, suppressing the activation of PSCs, reducing the secretion of TGF-t31, Collagen I , Ⅲ, FN and eventually inhibit the progress of pancreatic fibrosis.