低剂量电离辐射对小鼠下丘脑cAMP、cGMP及Fos蛋白表达的影响

目的　研究低剂量辐射对小鼠下丘脑cAMP、cGMP及Fos蛋白表达的影响。方法cAMP、cGMP和Fos蛋白分别采用竞争性蛋白结合分析、放免分析和免疫组织化学法。结果　 75mGyX射线全身照射后 ,小鼠下丘脑cAMP含量迅速增高 ,15min即达峰值 ,而后迅速回降 ,1h后接近假照射水平 ,以后出现小的波动 ;cGMP含量的变化基本与cAMP的变化相反 ;Fos蛋白在下丘脑诸多神经元核团内均呈阳性 ,照射后 8h达峰值 ,12h后逐渐减少 ,48h基本恢复至假照射水平。结论　提示低剂量辐射可激活小鼠下丘脑神经元的信号传递 ,进而调节免疫系统功能。

Effects of low dose radiation on cAMP, cGMP and Fos protein expressions in mouse hypothalamus

Objective\ In the present study we observed the effects of low dose radiation (LDR) on cAMP,cGMP and Fos expressions in mouse hypothalamus. Methods \ The changes of cAMP and cGMP contents as well as Fos protein expression in hypothalamus were determined using competitive protein binding assay,radioimmunoassay and immuno-histochemistry,respectively. Results \ The cAMP content in the hypothalamus increased rapidly after irradiation with 75 mGy X-rays.It reached its peak value at 15 min,and then returned to nearly normal value at 1 h,followed by small fluctuations.The changes of cGMP content were basically opposite to those of cAMP.The Fos protein was positive in a variety of neurons of hypothalamus after irradiation,and it reached the peak value at 8 h.Then it gradually returned to the control level 48 h after irradiation. Conclusion \ These findings suggest that LDR could influence the neuronal signal transduction in mouse hypothalamus with modulating functions on the immune system.