不同浓度酒精任氏液对蛙坐骨神经干双相复合动作电位的影响

Effects of Ringer’s solution with different concentrations of alcohol on biphasic compound action potentials of frog sciatic nerve trunk

目的:定量探究1%~80%酒精任氏液对蛙坐骨神经干双相复合动作电位(AP)的作用及其恢复情况。方法:制备长为6~8cm的蛙坐骨神经干标本,分别将含有0%、1%、2%、4%、8%、16%、32%、48%、64%、80%酒精的标准任氏液通过新加装在神经屏蔽盒中的加药液槽浸泡位于刺激电极和接地电极之间的神经干各5min,用BL-420F系统分别记录由刺激所诱发的双相AP;之后用标准任氏液冲洗5遍,浸泡5min,分别记录冲洗后AP。结果:与标准任氏液相比,≤4%酒精任氏液对AP峰值和传导速度无影响,≥8%酒精任氏液作用后可使AP峰值和传导速度均下降;16%、32%和≥48%酒精任氏液作用后分别使神经干失去产生AP能力的比例为30%、90%和100%。≤32%酒精任氏液作用后冲洗,AP峰值可完全恢复;48%、64%和80%酒精任氏液作用后冲洗,能恢复产生动作电位能力的比例分别为90%、40%和0%,平均峰值分别下降至正常的60%、36%和0%;冲洗后:≤8%酒精任氏液作用后的AP速度与正常无异,≥16%酒精任氏液作用后的AP速度无法完全恢复。结论:不同浓度酒精对AP峰值和传导速度影响不同,这对酒精的合理使用及过度使用后的损伤恢复有参考意义。

Objective: To quantitatively investigate the effects of Ringer’s solution with different concentrations of alcohol( 1%~80%) on biphasic compound action potentials( AP) from frog sciatic nerve trunk,and their recoveries from alcohol effects. Methods:Individual segments of frog sciatic nerve trunk with a length of 6 to 8 cm were prepared. Ringer’s solution with different concentrations of alcohol( 0%,1%,2%,4%,8%,16%,32%,48%,64% and 80%) was applied onto the segment of the trunk between the stimulus and ground electrodes via an agent reservoir which was newly armed in a nerve trunk shielded chamber for 5 minutes. The nerve trunk was respectively electro-stimulated to generate the biphasic compound AP which was recorded using the experimental system of BL-420 F. This was followed by 5 times washout plus 5 min administration with Ringer’s solution before recovery recording of AP. Results: Compared to normal Ringer’s solution,Ringer’s solution with alcohol at ≤4% did not have dramatic impacts on the AP amplitude and conduction velocity,while Ringer’s solution with alcohol at ≥8% there was significant decrease in these two parameters. Ringer’s solution with alcohol at the conentrations of 16%,32% and ≥48% could prevent a small proportion( 30%),a large proportion( 90%) and all( 100%) of sciatic nerve trunks,respectively,from generating AP. Washout with normal Ringer’s solution after alcohol application at the concentration of ≤32%,AP could totally recover to normal status. While alcohol at the concentration of 48%,64%and 80%,the probabilities to regenerate APs were 90%,40% and 0%,and the AP amplitudes were decreased to 60%,36% and0%,respectively. After washout,AP conduction velocity showed no difference with alcohol at the concentration of ≤8% when compared with that before washout,while it could not be recovered to normal under alcohol at ≥16%. Conclusion: Ringer’s solution with different concentrations of alcohol exerts different effects on biphasic compound AP amplitude and conduction velocity. Hopefully,our findings could be helpful for the alcoholic usage and its recovery from alcoholic damage.