热应激后猪血清中IL-2、IFN-γ及TNF-α水平的动态变化

Studies on the Dynamic Changes of the Level of IL-2,IFN-γ and TNF-α in Porcine Serum after Heat Stress

检测热应激后猪血清中的IL-2、IFN-γ及TNF-α水平,观察其变化规律.将12头体重基本一致的3月龄中国试验用小型猪随机分成高温试验组和常温对照组两组.高温试验组在人工气候仓内饲养,模拟夏季炎热气候,气温从26～39℃24 h循环变温,39℃时维持4 h;常温对照组在22℃下饲养.试验持续10 d,在热应激的第1、3、5、7、9天,39℃高温持续期结束的时刻采血,分离血清.用ELISA法检测各血清样品中IL-2、IFN-γ及TNF-α水平.结果显示：IL-2水平有所上升,且在热应激的第1天和第3天与常温对照组差异显著（P＜0.05）;IFN-γ水平有所下降,且在热应激的第3天和第5天与常温对照组差异显著（P＜0.05）;TNF-α水平有所上升,但与常温组比较差异不显著（P＞0.05）;热应激试验进行的10 d中,IL-2、IFN-γ及TNF-α水平变化有其共同特点,即随着试验的进行各细胞因子浓度都向常温对照组的正常值发展.本研究从细胞因子的角度验证了前人热应激抑制机体免疫机能的结论.

The effect of heat stress on the level of IL-2, IFN-γ and TNF-α in porcine serum were investigated in this study. Twelve healthy three-month-old pigs were divided into two groups at random, heat stress group and control group. The two groups were put into different AGCs（artificial climate chambers）, one of which simulated high temperature in summer （the temperature changed from 26℃ to 39℃ and lasted four hours at 39℃ ）, the other always keep at 22 ~C. The experiment lasted ten days and in the 1st, 3rd, 5th,7th and 9th day , 5 mL blood were drawn out of jugular vein soon after 39 ~C heat stress and level of IL-2, IFN-γ and TNF-α in porcine serum was determined by using ELISA. Contrast with the control group, the level of IL-2 in porcine serum of heat stress group increased dramatically （P〈0.05） on the 1st and the 3rd day after heat stress; The level of IFN-γ in porcine serum decreased dramatically （P〈0.05） on the 3rd and the 5th day ; The level of TNF-α in porcine serum of heat stress group increased,but not drammical ly. With the experiment going, the level of IL-2, IFN-γ and TNF-α in porcine serum of heat stress group increased or decreased gradually. On the 10th day, the level of these cytokines of the two groups was similar. The data presented indicated that heat stress restrained immune functions and the conclusion was in accordance with forepassed reports.