摘要
目的 :观察pH值对蟾蜍离体腓肠收缩能力的影响。方法 :采用D951生理实验教学系统 ,记录分析了置于 pH值为 6 .2、6 .4、6 .6、6 .8、7.0、7.2、7.4、7.6、7.8任氏液中的蟾蜍离体腓肠肌 (n =94 )的单收缩曲线。结果 :①蟾蜍腓肠肌收缩能力最佳的 pH值为 6 .8- 7.2 ;②pH值在 7.4 -7.8时 ,肌肉在初期出现强直收缩 ,且 pH值越高 ,强直收缩的持续时间越长 ;③随肌肉收缩的不断进行 ,舒张期时间逐渐延长 ,缩短期时间不变。结论 :蟾蜍腓肠肌在pH6 .8- 7.2之间收缩能力最佳 ,pH值过高或过低都将导致肌肉的收缩能力下降 ;肌肉舒张能力的降低是肌肉疲劳的主要特征之一。提示 :为防止肌肉疲劳应提高人体对酸的缓冲能力 ,但碱性物质的过量补充也可导致肌肉收缩能力下降 。
Objective It is the purpose of this article to observe the effects of different pH on contractility of toad gastrocnemius muscle that is continuously stimulated.Methods The single contraction curves of toad gastrocnemius muscles(n=94)stimulated continuously(912ms,7.5V)in Ringer solutions of different pH(6.2,6.4,6.6,6.8,7.0,7.2,7.4,7.6,7.8)have been recorded and analyzed respectively with D95 SURER LAB SYSTEM.Results ①The pH range of optimal contractility of toad gastrocnemius muscle is 6.8-7.2.②The tetanic contraction appears in the initial stages of the muscle contraction in the pH range from 7.4 to 7.8,the higher of the pH value,the longer of tetanic contraction duration.③The duration of muscle relaxation prolongs gradually with the muscle contraction proceeding,but the duration of shorting does not change.Conclusions The optimal pH range for toad gastrocnemius muscle contraction is 7.4-7.8.The contractility of the mucle drops in the pH over or under the range.The main character of muscle fatigue is reduction of muscle relaxing ability.It is suggested that in order to improve the performance ability,the buffer storage to acid must be enriched.But the over supplement of alkali substances also reduces the contractility of toad gastrocnemius muscle and induces tetanic contraction in the initial stages of the muscle contraction.
出处
《山东体育科技》
2003年第1期18-20,共3页
Shandong Sports Science & Technology
