Saito M, Ohmura M, Kondo A
Department of Urology, Nagoya University School of Medicine, Japan.
Neurourol Urodyn. 1996;15(2):157-65. doi: 10.1002/(SICI)1520-6777(1996)15:2<157::AID-NAU5>3.0.CO;2-E.
The effects of chronic partial outflow obstruction in rats were investigated. The urethra of male rats was partially obstructed for 3 or 6 months and bladder function was compared with that of age-matched controls. Bladder function was studied in vivo by infusion cystometry and in vitro by measuring the response of bladder muscle strips to stimulation. Cystometrograms of outflow-obstructed bladders were categorized into three types: type 1 was equivalent to a normal bladder; type 2 was characterized by large capacity, enhanced voiding pressure, and some residual urine; type 3 had the largest capacity, an impaired voiding pressure, and considerable residual volume (overflow-type of incontinence). The type 3 bladder was the most frequently observed type in rats obstructed for 6 months. Bladder weight increased significantly in rats with outflow obstruction. When five in vivo cystometric parameters (pressure at which micturition was induced, capacity, maximum voiding pressure, voided urine volume, and residual urine volume) were analyzed according to duration of obstruction, only two parameters (capacity and residual urine volume) in rats obstructed for 6 months differed significantly from those in age-matched controls. Evaluation of these values according to cystometric type showed a significant deterioration in four of five parameters in type 3 bladders. Contractile responses of the bladder in vitro to field stimulation, bethanechol, ATP, and KCI were significantly impaired in those obstructed for 3 or 6 months. When in vitro responses were analyzed according to the classification of cystometric type, deterioration of contractility was confirmed in both types 2 and 3 bladders. The present animal model of outflow obstruction can serve as a model of benign prostatic hyperplasia in humans.
研究了大鼠慢性部分性流出道梗阻的影响。雄性大鼠的尿道被部分梗阻3或6个月，并将膀胱功能与年龄匹配的对照组进行比较。通过灌注膀胱测压法在体内研究膀胱功能，并通过测量膀胱肌肉条对刺激的反应在体外进行研究。流出道梗阻膀胱的膀胱测压图分为三种类型：1型相当于正常膀胱；2型的特征是容量大、排尿压力增强且有一些残余尿；3型容量最大、排尿压力受损且残余尿量可观（溢出型尿失禁）。3型膀胱是梗阻6个月的大鼠中最常观察到的类型。流出道梗阻的大鼠膀胱重量显著增加。当根据梗阻持续时间分析五个体内膀胱测压参数（诱发排尿的压力、容量、最大排尿压力、排尿尿量和残余尿量）时，梗阻6个月的大鼠中只有两个参数（容量和残余尿量）与年龄匹配的对照组有显著差异。根据膀胱测压类型评估这些值显示，3型膀胱的五个参数中有四个显著恶化。在梗阻3或6个月的大鼠中，膀胱体外对场刺激、氨甲酰甲胆碱、ATP和氯化钾的收缩反应显著受损。当根据膀胱测压类型分类分析体外反应时，2型和3型膀胱的收缩力均证实恶化。目前的流出道梗阻动物模型可作为人类良性前列腺增生的模型。
