热应激时鸡糖皮质激素受体和热休克蛋白的变化

本研究应用3H-Dex放射配体结合的Scatchard分析和35S-蛋氨酸体外标记法分别测定了环境温度40℃热应激时，鸡外周血淋巴细胞(PBL)的糖皮质激素受体(GR)的最大结合容量(Ro)、平衡解离常数(Kd)及其热休克蛋白的表达。结果显示在热应激处理后0．5～4h鸡PBL、GR、Ro从85．75±10．09fmol／107细胞迅速下降至15．34±2．89fmol／107细胞。仅为正常对照组Ro的17．90％(P＜0．01)。与此同时细胞热休克蛋白(HSP)的合成持续增加，主要有HSP100，HSP90，HSP70和HSP25。而在热应激最初0．5h细胞总的蛋白合成急剧下降，随着应激时间的延长，HSP合成的增多，细胞总的蛋白也逐渐恢复。提示HSP在热应激过程中对细胞结构和机能的重建、维持激素与GR的亲合力，稳定受体蛋白结构，提高机体热耐受力具有重要意义。

Changes of glucocorticoid receptor and heat shock proteins in chickens with heat stress

This study was conducted fo determine the max-receptor binding capacity (Ro) and Kd of glucocorticoid receptor of peripheral blood lymphocytes (PBL) in chickens exposed to 40℃ ambient temperature for 0h, 5h, 1h, 2h and 4h by using Scatchard analysis of 3H-Dex specific binding. At the same time, the cellular proteins of PBL induced by heat stress were separated by using 35S-methionine in vitro labeling and Laemmli one-detention SDS-PAGE. The results showed that the Ro was rapidly reduced from 85.75±10.09 fmol/107 cells to 16.34±2.89 fmol/107 cells (P＜0.01), and the Kd was maintained at the level of 4.316±1.142 mol/L after heat stress. The cellular total proteins were sharply declined when the birds were exposed in elevated environmental temperature for 0.5h, but the heat shock proteins (HSP): HSP110, HSP90,HSP70 and HSP25 were induced. These HSPs were continuously increasing with the birds in elevated temperature to 4h. With the accumulation of HSPs in PBL, the total proteins of these cells were gradually recoved. The data suggest that HSPs play a more specific role in the reconstruction of the structure and function of cells, and can stabilize the construction of receptor proteins for preservation the affinity between GR and GC, and probably enhance the heat-resisting capability of cells.