局部注射BDNF对压力性尿失禁模型大鼠LPP及EUS内BDNF的影响

摘要

目的：探究阴部神经（PN）损伤后局部注入脑源性神经营养因子（BDNF）对压力性尿失禁模型大鼠漏尿点压力（LPP）及尿道外括约肌（EUS）脑源性神经营养因子表达的影响。方法：SD大鼠接受模拟分娩损伤和双侧卵巢切除，并建立压力性尿失禁模型。2周后评估模型建立是否成功。造模成功后，大鼠按照随机数字表法分为三组：BDNF组，损伤PN后局部注入BDNF，缝合后标记部位，第4、6、8天分别于标记部位再次注射；生理盐水组，损伤PN后局部注入生理盐水，量及方法同上；假损伤组，分离PN未损伤。2周后再次进行漏尿点压力及喷嚏实验。随后处死大鼠，取EUS行免疫组化，观察BDNF表达变化。结果：PN损伤后，统计学分析显示，生理盐水组LPP明显低于BDNF组和假损伤组，差异均有统计学意义（P<0.05）；而BDNF组与假损伤组比较差异无统计学意义（P>0.05）；HE染色显示，生理盐水组与假损伤组相比，肌纤维断裂及横纹肌排列致密程度均明显下降；免疫组化结果显示，假损伤组括约肌内BDNF含量低，与BDNF组及生理盐水组比较差异均有统计学意义（P<0.05），BDNF组与生理盐水组括约肌内BDNF含量比较差异无统计学意义（P>0.05）。结论：局部注射脑源性神经营养因子可能通过刺激神经再生从而促进尿道外括约肌的恢复，进而有利于压力性尿失禁大鼠LPP的恢复。%Objective:To investigate the effect of local injection of brain-derived neurotrophic factor(BDNF) on LPP and BDNF expression in external urethral sphincter(EUS)in stress urinary incontinence model rats after pudendal nerve(PN)injury.Method:SD rats received simulated birth trauma and bilateral ovariectomy,stress urinary incontinence model was established.After 2 weeks,we assessed the model success or not.After the success of modeling, the rats were randomly divided into three groups:the BDNF group,BDNF was local injected after PN injury,position were marked after suture,4,6,8 days the position were injected again;the saline group,the same amount of saline was local injected after PN injury;the sham group,the separation of PN without injury.After 2 weeks,we assessed LPP and sneezing experiments again.Then the rats were sacrificed,EUS was taken for immunohistochemistry,and the expression changes of BDNF were observed.Result:After PN injury,statistical analysis showed that,the LPP in saline group was significantly lower than that in BDNF group and sham group,the differences were statistically significant (P<0.05),there was no statistically significant difference between BDNF group and sham group(P>0.05).HE staining showed that the saline group compared with the sham group,muscle fiber fracture and striated muscle arrange compact degree decreased significantly.Immunohistochemical results showed that the content of BDNF in sphincter of sham group was significantly lower than the BDNF group and saline group,the differences were statistically significant(P<0.05), but there was no statistically significant difference between BDNF group and saline group(P>0.05).Conclusion:Local injection of brain-derived neurotrophic factor can stimulate the nerve regeneration so as to promote the recovery of external urethral sphincter,it is beneficial to the recovery of LPP in stress urinary incontinence rats.