Effect And Mechanism Research Of Electroacupuncture At Guanyuan Acupoint On Detrusor Urinae Of Rats Of Urinary Retention With Spinal Cord Injury

Objective: Accompanied by the rapid development of modern transport industry and construction industry,which facilitate the people's life and manufacture, On the other hand, the hidden trouble of health and safety stand out increasingly. The high attack rate phenomenon of spinal cord injury caused by trauma accident is one of the performances.Spinal cord injury has the peculiarity of high rate of disability in lifetime and difficult treatment.Its complication, urinary retention, makes the life quality of spinal cord injury patient descend more,even threaten their lives.So,the treatment of urinary retention with spinal cord injury has become a problem paid highly attention by medicine researcher.Now, a good many of clinical research has approved that acupuncture treatment has the affirmative curative effect on this disease. Relative to western medicine, acupuncture treatment has unique advantage on the disease, but the mechanism have not been made clear. The purpose of our experiment is to study the effect of electroacupuncture at Guanyuan acupoint on the ultrastructure of detrusor urinae,apoptosis and related gene(bax,bcl-2), excitability of detrusor urinae and expression level ofα-smooth muscle actin(α-SMA) in detrusor urinae and brain-derived neuro-trophiefactor(BDNF) and tropomyosine receptor kinase B(TrkB) in spinal cord of rats of urinary retention with spinal cord injury, and discuss the possible mechanism of point electroacupuncture treat this disease.Methods: In experiment one, adult healthy SD female rats were randomly divided into normal group, model group, electroacupuncture treatment group, 5 rats in each; In experiment two,three and four, adult healthy SD female rats were randomly divided into normal group, sham operation group, model group, electroacupuncture treatment group and electroacupuncture control group,20 rats in each.Established model rats of urinary retention after spinal cord injury by the classic weight drop method.When the spinal cord was stricken, the rat's body occurred spastic shiver and the tail spastic swing,and more the body and both lower extremities occurred retraction flutter-like. The rat's body was in the spinal shock stage immediately after spinal cord injury,when the detrusor urinae was in the state of no reflex or low reflex,and bladder micturate feebly. Above the pubic symphysis in abdomen area,the puffy bladder could be touched in 24 hours after the operation of model making, namely the model was successful. Electroacupuncture treatment group chose Guanyuan point and electroacupuncture control group chose Shuidao point.when the rats in sham operation group were exposed the centrum of T₆-T₁₀,didn't make injure any more and seam directly after 5 minites.Use MP150WSW 16 channel physiologic recorder stimulate output module when treating.Adopted density-wave,2Hz/15Hz frequency and 1mA intensity. When the model making operation was finished and after 24 hours, gave the first electroacupuncture treatment and another every 24 hours, 10 times totally,and stimulated 20 minites constantly every time. Respectively applied electron microscope to observe the ultrastructure of cell and tissue of detrusor urinae; Applied terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and immunohistochemistry SP method to observe the rats detrusor urinae apoptosis and apoptosis related gene bcl-2 and bax expression; Used the invitro detrusor urinae muscle strips experiment to determine the minimum contraction tension and frequency of contraction of invitro detrusor urinae,observed excitability of detrusor urinae,and by the immunohistochemistry SP method, determined the expression ofα-SMA in muscular layer of detrusor urina, observed its contraction ability; By immunohistochemistry SP method, determined the expression of BDNF and TrkB in spinal cord injured.All the data were input into computer and dealt with SPSS13.0 statistical analysis software.Variance analysis of one way or R×C form chi-square test was used in the comparison among multi-group data.Examination standard,namely a was 0.05,and P<0.05 meant its had statistical significance.Experiment results were showed by mean±standard deviation((x|-)±S).Results: (1) Compared with normal group,the main change of ultrastructure of detrusor urinae in model group was that cell arrangement was in disorder, the chromatin in the cell nucleus centralized side and concentrate,and many mitochondrion had oedema, rough surfaced endoplasmic reticulum had obvious dilatation,oedema and local vacuolization, and what's more, collagenous fibers increased a lot among cell of smooth muscle. After electroacupuncture Guanyuan treatment, ultrastructure of detrusor urinae had much more change in comparison with model group,and the change of the mitochondrion, rough surfaced endoplasmic reticulum and collagenous fibers were the most distinct.The manifestation was that the degree of oedema in mitochondrion and dilatation in rough surfaced endoplasmic reticulum lessened obviously,and the amount of collagenous fibers among cell of smooth muscle decreased distinctly, and cell arrangement become regular. ( 2 ) In the observation of apoptosis, the normal group and sham operation group showed low expression of apoptosis,and there were no significant differentce in the two group(P>0.05). Apoptosis index (AI) of model control group was higher than the normal group(P<0.05).The AI of electroacupuncture at the Guanyuan treatment group was lower than the model control group and electroacupuncture at Shuidao control group(P<0.05).Guanyuan group bax protein expression was less than the Shuidao group and the model control group(P<0.05). Guanyuan Group bcl-2 protein expression had no significant differentce in comparison with the Shuidao group and model control group(P>0.05). (3 ) Compared to normal group and sham operation group,the minimum contraction tension in model group increased, and the frequency of contraction decreased(P<0.05); Compared to normal group and sham operation group, there was no significant difference(P>0.05).Compared to model group,the minimum contraction tension in electroacupuncture group reduced significantly, and the frequency of contraction increased (p<0.05). The difference between Guanyuan group and Shuidao group had statistical significance(P<0.05).In the observation ofα-SMA expression of detrusor urinae in any field of vision under optical microscope, all groups showed positive expression. The normal group and sham operation group displayed strong positive expression, and model control group showed weak positive expression, which was lower than the normal group and had a spot of scattered plaquelike area of strong positive expression.Both the electroacupuncture at Guanyuan group and electroacupuncture at Shuidao control group showed medium positive expression in major area of any field of vision,which had a spot of scattered plaquelike area of strong positive expression,and these areas of Guanyuan group were more than Shuidao control group and model control group. (4) In the observation of the expression level of BDNF and TrkB in spinal cord in each group,in both BDNF and TrkB expression,model group exceeded the normal and sham group, both of the Guanyuan and Shuidao group obviously exceeded the other groups,which had significant difference(P<0.05),and Guanyuan group was higher than the Shuidao group(P<0.05).Conclusion: These factors,which are the change of ultrastructure of detrusor urinae, the happen of apoptosis, related genes of apoptosis(bcl-2 and bax), the change of detrusor urinae excitability, a-SMA,BDNF and TrkB,all take part in the happen and development process of urinary retention with spinal cord injury. To the pathological state of detrusor urinae of rats of urinary retention with spinal cord injury, the treatment of electro-acupuncture at Guanyuan point has a good effect of adjustment. The effect realizes presumably by the path: (1)ultrastructure of cell and tissue of detrusor urinae is improved; (2)reduce the expression of accelerated apoptosis gene, thus the apoptosis of detrusor urinae decreases; (3)the excitability of detrusor urinae is enhanced effectively,and the ability of contraction emiction of bladder is reenforced; (4)Accelerate the repair of nerve-cell of spinal cord injured and nerve tract of spinal cord which can conduct micturition reflex impulse. Point electro-acupuncture treatment can improve the pathological state of low-reflex or non-reflex bladder detrusor urinae of rats of urinary retention with spinal cord injury by multi-link and multi- level.