黄芪水煎剂对免疫应激鸡血清ACTH和CORT含量及下丘脑CRH mRNA表达的影响

Effects of Astragalus water decoction on expression of hypothalamic CRH mRNA and serum levels of ACTH and CORT in immune stress laying hens

研究了黄芪水煎剂对实验性免疫应激鸡下丘脑血清中促肾上腺皮质激素(ACTH)和皮质酮(CORT)含量及促肾上腺皮质激素释放激素(CRH)mRNA表达水平的影响。试验分为空白组、对照组和黄芪低、中、高剂量组。黄芪组于30日龄开始早晚2次口服黄芪水煎剂,给药剂量为低、中、高3组每天剂量分别为0.5、1、1.5g生药/只,连续7d。对照组、黄芪组于32日龄胸肌注射接种10×剂量的新城疫Ⅰ系疫苗(NDVⅠ),造成实验性免疫应激;空白组注射等量生理盐水。分别于免疫接种后的1、3、5、7、14、21d每组随机取8只鸡,进行心脏采血,取下丘脑。ELISA检测免疫应激后血清中ACTH和CORT含量;RT-PCR测定下丘脑CRH mRNA表达水平。结果显示,对照组注射大剂量新城疫Ⅰ系疫苗后,可引起血清中ACTH和CORT的含量和CRH mRNA的表达水平都显著升高,造成了实验性免疫应激。黄芪低剂量组对免疫应激的缓解作用不明显,而黄芪中、高剂量组对免疫应激有显著的缓解作用。结果表明,注射大剂量新城疫Ⅰ系疫苗可引起鸡的免疫应激,一定剂量的黄芪水煎剂可以缓解新城疫Ⅰ系疫苗引起的免疫应激。

The study was to investigate the effect of wild chrysanthemum water decoction on expression of hypothalamic CRH mRNA and serum levels of ACTH and CORT in immune stress broiler chicks.Test was divided into blank group,control group and Astragalus group including low,medium and high dose groups.Astragalus group was drank Chinese medicine decoction sooner or later two times for 7days.The doses of low,medium and high dose groups were respectively0.5,1and 1.5g per bird per day.Control and Astragalus groups were vaccinated with 10 Newcastle disease Ⅰvaccine（NDV Ⅰ）by inteamuscular injection on 32-day-old to cause experimental immunological stress,at the same time,blank group injected with equivalent saline.Each group randomly selected eight chickens to collect blood by the heart and take hypothalamus after immunization 1,3,5,7,14,21 days.The content of ACTH and CORT were measured by the double antibody sandwich enzyme-linked immunosorbent assay step（ELISA）.The expression of CRH mRNA was measured by real-time quantitative PCR.The results showed that control group has a significantl increase in the expression of CRH mRNA and the content of ACTH and CORT after the immunity of 10 NDV Ⅰ,displaying experimental immunological stress.The mitigative effect of low dose group is not obvious,but the medium and high dose groups have a good effect on alleviating the immune stress.In conclusion,the harge dose of NDV Ⅰcan caused experimental immunological stress,and a suitable dose of astragalus water decoction can relieve it.