Improvement of electroacupuncture in urinary function of rats with suprasacral cord injury by regulating the expressions of serotonin receptors in the smooth muscles of the bladder and urethra
Objective To observe the maximum cystometric capacity(MCC)and leakage point pressure(LPP)of rats with suprasacral cord injury(SSCI)after electroacupuncture(EA)treatment,and to analyze the expressions of different subtypes of serotonin 5-hydroxytryptamine(5-HT)receptors in the detrusor and internal urethral sphincter(IUS),so as to explore the effect mechanism of EA in regulating the urinary function of rats with detrusor sphincter dyssynergia(DSD)through postsynaptic 5-HT receptors.Methods Twelve of 36 SD female rats were randomly selected as blank group.The remaining 24 rats were made into SSCI models by modified Hassan Shaker spinal cord transection at T10 segment,which were randomized into model group and EA group after modeling,with 12 rats in each.EA group was given continuous EA stimulation at the acupoints of"Ciliao(BL32)""Zhongji(CV3)"and"Sanyinjiao(SP6)"for 40 min,once a day,for consecutive seven days;blank and model groups were only bound without any treatment.The urodynamic test was performed by cystostomy.After the rats were sacrificed,tissues of the detrusor and proximal urethra were taken,then Western blot was used to check the content of 5-HT receptors in them.Results The MCC and LPP of model group were significantly higher than those of blank group(P＜0.01);the MCC of EA group was significantly lower than that of model group and higher than that of blank group(P＜0.01),and the LPP was significantly lower than that of model group(P＜0.01).Compared with blank group,the expression of 5-HT1A receptor showed a significant decrease in the detrusor of model group(P＜0.01)and a significant increase in the IUS(P＜0.01).The expression of 5-HT1A receptor in the detrusor of EA group was significantly higher than that of model group(P＜0.01),and its expression in the IUS of EA group was lower than that of model group(P＜0.05),but still significantly higher than that of blank group(P＜0.01).The expression of 5-HT2B receptor in the detrusor of model group was higher than that of blank group(P＜0.05);its expression in the detrusor of EA group was lower than that of model and blank groups(P＜0.05).Compared with blank group,the expression of 5-HT7 receptor in the detrusor significantly decreased(P＜0.01)and that in the IUS significantly increased(P＜0.01)in the model group;its expression in the detrusor and IUS of EA group was lower than that of model group(P＜0.05).Conclusion EA stimulation at the acupoints of"Ciliao(BL32)""Sanyinjiao(SP6)"and"Zhongji(CV3)"of DSD rats after SSCI can induce changes in the expressions of 5-HT receptors in the smooth muscles of the bladder and urethra.5-HT1A and 5-HT2B receptors may cause phasic and/or tonic contractions of smooth muscles through Ca2+influx;5-HT7 receptor may mediate the smooth muscle relaxation by altering the big conductance Ca2+-activated K+(BK)channel activity through cyclic adenosine monophosphate(cAMP)pathway.EA treatment may improve the lower urinary tract function in DSD rats after SSCI by inhibiting overactivity of the detrusor,increasing its contractility,and coordinating urethral resistance through the above mechanism.
万方数据
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