Objective To explore the relationship between the expression of nerve growth factor (NGF) in bladder tissue of Sprague-Dawley rats with diabetes mellitus and the changes of bladder structure and urodynamics.Methods Sixty-three Sprague-Dawley rats were selected and divided into diabetic group (n =33) and control group (n =30).The diabetes mellitus model was made by injecting of steptozotocin (STZ) into the tail vein of rats in the diabetic group;the rats in control group were injected the same volume of citrate buffer solution.The 24 h urinary volume was detected by using metabolic cage;the function of bladder was detected by using Medlab bio-signal collection system;the expression of NGF in the bladder tissue of rats was detected by Western blot;the bladder structure was observed by using light microscope and transmission electron microscope (TEM).Results Four,eight and twelve weeks after the success of diabetic rat model,the level of blood glucose of rats in diabetic group was significantly higher than those in the control group (P ＜ 0.05);the body weight of rats in diabetic group was significantly lower than that in the control group (P ＜ 0.05).The 24 h urinary volume of rats in diabetic group was significantly increased compared with control group (P ＜ 0.05).The maximum capacity of bladder and residual urine volume of bladder and elasticity of bladder of rats in diabetic group were significantly higher than those in the control group (P ＜ 0.05);the maximum bladder pressure of rats in diabetic group was significantly lower than that in the control group (P ＜ 0.05);and the changes of all above indexes of rats in diabetic group were time-dependent(P ＜ 0.05).The expression of NGF in bladder tissues of rats in diabetic group was significantly lower than that in the control group (P ＜ 0.05),and the change of NGF expression in diabetic group was time-dependent (P ＜ O.05).In diabetic group,the bladder smooth muscle was hypertrophic,the organization of smooth muscle was diverse and lose,and the muscle bundle fracture was observed;in control group,the bladder smooth muscle arranged orderly,and the shape was consistent,the structure of fascicle was compact.The condensation and margination of nuclear chromatin and mitochondria swelling were observed in diabetic group;while the bladder tissues in control group showed homogeneous nuclear and mitochondria without fracture and swelling.Conclusion The decrease of the expression of NGF in bladder tissues of diabetic rats can decrease the systolic function of bladder and change the morphology of detrusor and these changes show a time dependence.%目的 研究糖尿病大鼠膀胱组织中神经生长因子(NGF)的表达与膀胱结构改变和尿流动力学变化的关系.方法 选择Sprague-Dawley大鼠63只随机分为糖尿病组33只和对照组30只.糖尿病组大鼠尾静脉注射链脲佐菌素(STZ)制作糖尿病大鼠模型,对照组大鼠尾静脉注射等量柠檬酸缓冲液.应用代谢笼检测2组大鼠24h尿量,Medlab生物信号采集处理系统检测膀胱功能,Western blot法检测大鼠膀胱组织中NGF表达,并利用光学显微镜及透射电镜观察膀胱结构的变化.结果 糖尿病大鼠模型制备成功后4、8、12周,糖尿病组大鼠血糖较对照组显著升高,体质量较对照组显著下降(P＜0.05),24 h尿量较对照组显著增多(P＜0.05);尿流动力学检查显示,糖尿病组大鼠膀胱阈容量、残余尿量及膀胱顺应性显著增加,最大膀胱内压显著降低,并呈时间依赖性(P＜0.05).Western blot结果显示,糖尿病组大鼠膀胱组织中NGF表达较对照组显著下降(P＜0.05),且随着病程延长,NGF表达逐渐降低.苏木精-伊红染色结果显示,光镜下糖尿病组大鼠膀胱平滑肌肥大,形态多样,排列紊乱疏松,可见肌束断裂,随着病程延长,变化更加明显;对照组大鼠膀胱平滑肌肌束排列整齐,形态一致,肌束间结构紧密.电镜下糖尿病组大鼠膀胱平滑肌细胞的细胞核染色质出现边集,核周隙不清,线粒体肿胀;对照组大鼠膀胱细胞核染色质均匀,核周隙清晰,线粒体膜无破裂、无肿胀.结论 糖尿病大鼠膀胱组织中NGF表达下降诱导膀胱出现收缩功能减弱及逼尿肌形态学改变,并呈现时间依赖性.
展开▼
