RU_(486)对地塞米松诱导鸡淋巴细胞免疫抑制的逆转效应

给２０日龄雏鸡注射不同剂量糖皮质激素（ＧＣ）制剂———地塞米松（Ｄｅｘ），结果不同剂量的Ｄｅｘ对鸡淋巴细胞免疫功能都产生明显的抑制效应；体外试验进一步证明Ｄｅｘ能抑制鸡脾淋巴细胞的刺激增殖活性，用１０－７ｍｏｌ／Ｌ浓度的ＲＵ４８６（ｍｉｆｅｐｒｉｓｔｏｎ）阻断鸡淋巴细胞糖皮质激素受体（ＧＲ）则可逆转这种抑制效应。试验证明２５ｍｇ／ｋｇ体重剂量的ＲＵ４８６在鸡体内有拮抗Ｄｅｘ抑制鸡体免疫功能的作用，从而证实ＧＣ诱导鸡淋巴细胞免疫功能降低是由淋巴细胞的ＧＲ介导的。所以，部分阻断ＧＲ可防止鸡体因ＧＣ升高所导致的免疫力下降，这对提高鸡的疫苗免疫效果及应激状态下抗病力有理论指导意义。

Reversed Effect of RU 486 on chicken's Lymphocytic Immunosuppressioninduced by Administration of Dexamethason

After 20 dayold chicks were injected with different dosages of glucocorticoid (GC) preparation dereamethason (Dex), all showed obviously suppressed effects of the lymphocytic immunity function induced by the various dosages of Dex. And in tests in vitro it was further proved that Dex was able to inhibit chick's splenic lymphoprotiferation activity significantly, but a dose of 10-7 mol/L of RU486 made this immunosuppression reverse by means of blocking chick's glucocorticoid receptor (GR). Therefore, it was showed that taking 25 mg RU486/kg body weight to chicks is able to resist Dex and to prevent from Dexcaused immunosuppression effect for chicks, and at the same thime it was also confirmed that GCcaused drop of chick's immune function was mediated by GR derived from lymphocytes. And the partial blocking GR might prevent from a decrease of chick's immunity due to increase of GC, which has a theoreticaldirectional significance for elevating immunozation efficacy of vaccine for chicks and improving chick's resistance to diseases under a certain state of stress.