电针对骶上脊髓损伤后逼尿肌亢进大鼠逼尿肌中环腺苷酸和蛋白激酶A含量及肌球蛋白轻链激酶磷酸化的影响

Effect of Electroacupuncture on Content of Cyclic Adenosine Monophosphate and Protein Kinase A,and Phosphorylation of Myosin Light Chain Kinase in Detrusor of Rats with Detrusor Hyperreflex after Suprasacral Spinal Cord Injury

目的探讨电针改善骶上脊髓损伤休克期后逼尿肌反射亢进的可能机制。方法60只雌性Sprague-Dawley大鼠按随机数字表抽取12只作为空白组,12只作为假手术组,剩余36只采用改良T10脊髓横断法制作神经源性膀胱模型,从符合要求的模型大鼠中二次随机抽取12只作为模型组,12只作为电针组。造模术后第19天取次髎、中极、三阴交行电针干预,连续治疗7 d后行尿流动力学检测,ELISA法测定逼尿肌环腺苷酸(cAMP)、蛋白激酶A(PKA)含量、Western blotting法测定逼尿肌磷酸化肌球蛋白轻链激酶(p-MLCK)水平。结果与空白组和假手术组比较,模型组膀胱最大容量及膀胱顺应性明显降低(P<0.01),膀胱基础压和漏尿点压明显升高(P<0.01);逼尿肌cAMP和PKA含量明显降低(P<0.01),逼尿肌p-MLCK水平明显降低(P<0.01)。与模型组比较,电针组膀胱最大容量及膀胱顺应性明显增加(P<0.01),膀胱基础压和漏尿点压降低(P<0.05);逼尿肌内cAMP和PKA含量升高(P<0.05),逼尿肌p-MLCK水平升高(P<0.05)。结论电针次髎、中极、三阴交穴可改善完全性脊髓损伤后逼尿肌亢进大鼠膀胱功能,其作用机制可能与电针上调逼尿肌中cAMP、PKA表达,使MLCK磷酸化而失活,从而促进逼尿肌舒张有关。

Objective To explore the possible mechanism of electroacupuncture to improve detrusor hyperreflex after suprasacral spinal cord injury.Methods A total of 60 female Sprague-Dawley rats were included.According to the random number table,twelve were selected as the blank group,twelve as the sham operation group,and the remaining 36 were made neurogenic bladder models using modified T10 spinal cord transection.After that,twelve of them were randomly selected as the model group and twelve were as the electroacupuncture group from the model rats that met the requirements.On the 19th day after modelling,Ciliao(BL32),Zhongji(RN3)and Sanyinjiao(SP6)were taken for electroacupuncture.After seven days of continuous treatment,urodynamic testing was performed,content of cyclic adenosine monophosphate(cAMP)and protein kinase A(PKA)in detrusor was determined by ELISA,and the level of phosphorylation of myosin light chain kinase(p-MLCK)of detrusor was determined by Western blotting.Results Compared with the blank group and the sham operation group,the maximum bladder capacity and bladder compliance significantly reduced(P<0.01),and the base pressure and leakage point pressure of bladder significantly increased(P<0.01);the content of cAMP and PKA in detrusor reduced(P<0.01),p-MLCK in detrusor reduced(P<0.05)in the model group.Compared with the model group,the maximum bladder capacity and bladder compliance increased(P<0.01),the base pressure of the bladder and the pressure at the leak point decreased(P<0.05);the contents of cAMP and PKA protein in detrusor increased(P<0.05),the p-MLCK in detrusor increased(P<0.05)in the electroacupuncture group.Conclusion Electroacupuncture at Ciliao,Zhongji and Sanyinjiao points could improve the bladder function of rats with detrusor hyperreflex after complete spinal cord injury,and its mechanism may be related to up-regulating the expression of cAMP and PKA,phosphorylating and inactivating p-MLCK,which promote relaxation of detrusor.