自由活动大鼠脑内次黄嘌呤的活体在线电化学分析方法研究

On-line electrochemical measurements of cerebral hypoxanthine of freely moving rats

本文通过联用选择性的电化学传感器和活体微透析采样技术,提出并建立了自由活体大鼠脑内次黄嘌呤的在线电化学分析新方法.本研究中,次黄嘌呤被黄嘌呤氧化酶(XOD)催化氧化,同时产生H2O2.利用普鲁士蓝(PB)作为H2O2电化学还原的催化剂,通过测定H2O2,从而实现了次黄嘌呤的在线电化学分析.实验结果表明,所建立的方法具有很好的选择性、稳定性和重现性,可以应用于自由活动大鼠脑内次黄嘌呤的连续测定.本文的研究为与次黄嘌呤相关生理和病理过程分子机制的研究奠定基础.

This study demonstrates an on-line method for continuous measurements of cerebral hypoxanthine in the freely moving rats with integration of selective electrochemical biosensing with in vivo microdialysis sampling. The selective electrochemical biosensing is achieved by using xanthine oxidase （XOD） as the specific sensing element and Prussian blue （PB） as the electrocatalyst for the reduction of H2O2 generated from the oxidase-catalyzed reaction. The method is virtually interference-free from the coexisting electroactive species in the brain and exhibits a good stability and reproducibility. Upon integrated with in vivo microdialysis, the on-line method is well suitable for continuous measurements of cerebral hypoxanthine of freely moving rats, which is illustrated by the measurements of the microdialysates after the hypoxanthine standard was externally infused into the rat brain. This study essentially offers a facile on-line electrochemical approach to continuous measurements of cerebral hypoxanthine and could find some interesting applications in physiological and pathological investigations associated with hypoxanthine.