ACTH肌注建立鸡免疫抑制模型及其评价

连续7 d给鸡肌肉注射不同剂量(15、30、45 IU·kg-1·d-1)的ACTH(adrenocorticotropic hormone)后,通过生理学和免疫学指标对该模型进行了评价。结果显示,45 IU·kg-1·d-1处理组的血清皮质酮浓度、肾上腺指数均显著高于对照组(P<0.05);而血清IgG、IgA、IL-2、IFN-γ水平,胸腺、脾脏和法氏囊指数,组织IgG和禽β-防御素6生成量均显著低于对照组(P<0.05);处理组的血糖值仅在注射ACTH后2 h显著高于对照组(P<0.05),其他时间差异不显著。本研究表明,15、30、45 IU·kg-1·d-1的ACTH连续7 d肌肉注射可引起鸡应激性免疫抑制。血清皮质酮升高、肾上腺肥大和肾上腺皮质细胞增生肥大可用于评价持续应激,而血糖不适合评价持续应激;免疫抑制评价指标包括免疫器官萎缩,组织中免疫细胞数量、IgG和禽β-防御素6生成量下降,以及血清IgG、IgA、IFN-γ和IL-2水平降低。

Evaluation and establishment of chicken immunosuppressive model by intramuscular injection of adrenocorticotropic hormone

After chickens were continuously injected with ACTH at 15,30 and 45 IU·kg-1·d-1 for 7 days separately,a model was set up and evaluated by the physiological and immunological parameters.The results show that the concentration of serum corticosterone and adrenal indexes of the treatment group injected with ACTH at 45 IU·kg-1·d-1 were greater compared with those of the control group(P<0.05);the level of serum IgG,IgA,IL-2,IFN-γ,organ index of thymus,spleen,bursa of Fabricius,and generation of IgG and chicken-defensin 6 were lower than those in the control group(P<0.05);the blood glucose of the treatment group was significantly higher than that of the control group only after two hours of injection(P<0.05),and there were no difference among the treatment groups with different time.This study suggests that the intramuscular injection of ACTH to chicken with 15,30 and 45 IU·kg-1·d-1 for 7 days consecutively can cause stress-induced immunosuppression.The exaltation of serum corticosterone,the hypertrophy of adrenal,and the hyperplasia and hypertrophy of adrenocor-tical cells,can be used to evaluate the continuous stress,but blood glucose is not suitable.The parameters of im-munosuppression include the atrophy of immune organ,decrease in the number of immune cells,IgG and avian beta-defensin-6,and decline in the content of IgG,IgA,IFN-γ and IL-2 in serum.