直流电刺激下组织培养液的电化学反应

Electrochemical Reactions in Tissue Culture Medium under the Direct Current Stimulation

直流电刺激的方法在促进骨折愈合、神经纤维生长、感染性创伤治疗等方面,已得到广泛的应用。基础研究中往往通过观察直流电流对体外培养细胞生长分化和代谢的影响,来探讨其作用机制。本实验的重点是了解直流电刺激下组织培养液的电化学反应.实验中用自制MCDC—1型直流电刺激仪,选择临床常用电流强度(20μA),观察到组织培养液阻抗值随刺激时间呈指数曲线增加。阴极极化曲线分析显示,刺激电流密度小于85μA/cm^2时,培养液内无电化学反应发生,85～212μA/cm^2之间,出现电化学反应,阴极以氧气还原反应为主O:_2+2H_2O+4e→40Hˉ电流密度大于212μA/cm^2时,阴极电化学反应骤然增加,伴有氢气析出,阴极区液体pH值随电流密度及刺激时间增加而升高。

Direct current stimulation has been widely used in the trea(?)ment of bone fractures, peripheral nerve injury and infected wound. Some basic researches on the mechanism of direct current stimulation have been carried out by the technique of in vitro cellular culture. In the present study, we explored the electro-chemical reactions in tissue culture medium under the direct current stimulation.Two Platinum electrodes with an effective surface of 20mm2 in each were separated 35mm apart and im-mersed in RPMI 160 and 10% fetal bovine serum medium. Current intensity of 20 microamperes was gener-ated by the micro -constant direct current stimulator(MCDC-1). Culture medium resistance increased wtth the stimulating time. Analysis of the cathodic polorization reaction curve showed: when the stimulating cur-rent density was less than 85μA/CM2,no electrochemical reactions took place in the culture medium; when it was between 85 - 212μA/CM2 ,some electrochemical reactions occurred in the culture medium, of which, O2 + 2H2O+4e-→4OH- ,was identified as the major reaction in the culture medium near the cathodic electrode; when the density was larger than 212μA/CM2, the electrochemical reactions increased sharply with the re-lease of hydrogen (H2). The pH values in the cathodic electrode region increased with the stimulating time and current density.