糖尿病大鼠尿道功能损害以及病程对其的影响

The Effect of Diabetes Mellitus Term on Urethral Dysfunction in Rats

利用大鼠模型研究糖尿病对尿道功能的损害,以及病程长短对其的影响.雌性SD大鼠（250-275 g）,链脲霉素（STZ）65 mg/kg腹腔注射得到糖尿病大鼠模型,5周或10周后在乌拉坦麻醉下利用三导管系统,隔离地测定STZ-糖尿病大鼠和正常对照大鼠膀胱等容收缩状态下的膀胱内压,尿道充盈压和括约肌肌电图（EUS-EMG）.静脉注射横纹肌阻断剂-αbungarotoxin（BGT）后再次测定.与正常对照大鼠对比,5周和10周糖尿病大鼠膀胱内压峰值及平滑肌收缩幅度明显降低,并且尿道括约肌的高频振动收缩（HFOs）出现不规则变化.有3只（27%）5周的糖尿病大鼠和3只（33%）10周的糖尿病大鼠出现逼尿肌-括约肌失协调（detrusor-sphincter dyssyn-ergia,DSD）.BGT阻断尿道外括约肌后,糖尿病大鼠的尿道充盈压（UPP）有更明显的下降.提示了糖尿病损伤尿道括约肌功能,引起排尿时尿道阻力增加,导致排尿功能的损伤.早期干预有助于防止糖尿病引起的排尿功能的进一步恶化.

The effects of short- and long-term diabetes mellitus （DM） on urethral dysfunction were investigated, which may worsen voiding dysfunction in diabetic cystopathy. The DM rat were gotten by injecting 65 mg/kg of STZ in female Sprague-Dawley rat（250-275 g）, 5 and 10 weeks after DM induction with streptozotocin, female Sprague-Dawley rats and their age-matched controls were studied under urethane anesthesia. Isovolumetric bladder pressure, anterograde urethral pea＇fusion pressure （UPP）, and external urethral sphincter electrornyography （EUS-EMG） activity were measured using a preparation that functionally separated the urethra from the bladder. The responses of the urethra to intravenous administration of the skeletal muscle blocker α-bungarotoxin （BGT） were determined. The isovolumetric peak bladder pressure and contraction amplitude were significantly decreased in both 5- and 10-wk DM rats. Whereas control rats showed high-frequency oscillations （HFOs） of UPP with uniform frequency and amplitude, DM rats had an irregular pat- tern of FIFOs with variable amplitude. Detrttsor-sphincter dyssynergia （DSD） occurred in 3/11 and 3/10 of 5- and 10-wk DM rats only. BGT treatment caused a greater reduction of baseline UPP in 5- and 10-wk DM rats than in controls. The study demonstrated remarkable striated EUS dysfunction, which may cause the increase of urethral resistance and worsen the voiding dysfunction in DM. Early intervention may he important in preventing permanent damage to the voiding function in DM.