Streng T, Launonen A, Salmi S, Saarinen N, Talo A, Mäkelä S, Santti R
Department of Anatomy, Institute of Biomedicine, University of Turku, Turku, Finland.
J Urol. 2001 Apr;165(4):1305-9.
Bladder outlet obstruction develops in estrogen treated males. Because of the lack of electromyography recordings, earlier studies have not clarified the failure mechanisms of voiding. We simultaneously recorded electromyography activity of the proximal rhabdosphincter in neonatally estrogenized rats with transvesical cystometry and urethral flow, followed by morphometric analysis of the urethral structure.
Rats treated neonatally with 10 microg. diethylstilbestrol daily on days 1 to 5 after birth were used in urodynamics and morphological studies at ages 5 to 6.5 months. Using anesthesia the bladder, anterior surface of the proximal rhabdosphincter and distal urethra were exposed to record simultaneously the high frequency oscillations of intraluminal bladder pressure, and the rates of intermittent flow from the distal urethra and electromyography activity of the proximal rhabdosphincter with a suction electrode.
Neonatally estrogenized rats had higher mean maximal bladder pressure plus or minus standard deviation (42.1 +/- 6.4 versus 37.7 +/- 4.9 mm. Hg, p = 0.01), decreased mean flow (2.3 +/- 0.1 versus 4.1 +/- 1.6 ml. per minute, p < 0.0001) and mean increment of proximal rhabdosphincter electromyography depolarization amplitude (3.0 +/- 0.78 versus 2.6 +/- 0.87 mV., p = 0.02) compared with controls, while mean transient repolarization was absent or highly decreased (-0.3 +/- 0.61 versus 0.3 +/- 0.9 mV., p = 0.04). Morphologically the proximal rhabdosphincter was atrophied with increased connective tissue.
Alterations in the structure and electromyography activity of the urethral musculature imply that neonatal exposure to diethylstilbestrol predisposes male rats to urethral atrophy and dyssynergia, evident as altered electromyography activity of the proximal rhabdosphincter.
雌激素处理的雄性大鼠会发生膀胱出口梗阻。由于缺乏肌电图记录，早期研究尚未阐明排尿失败的机制。我们通过经膀胱膀胱测压和尿道流量，同时记录新生期经雌激素处理大鼠近端横纹括约肌的肌电图活动，随后对尿道结构进行形态计量分析。
出生后第1至5天每天用10微克己烯雌酚对新生大鼠进行处理，在5至6.5个月龄时用于尿动力学和形态学研究。使用麻醉暴露膀胱、近端横纹括约肌前表面和远端尿道，用吸引电极同时记录腔内膀胱压力的高频振荡、远端尿道的间歇性流速以及近端横纹括约肌的肌电图活动。
与对照组相比，新生期经雌激素处理的大鼠平均最大膀胱压力加或减标准差更高（42.1±6.4对37.7±4.9毫米汞柱，p = 0.01），平均流速降低（2.3±0.1对4.1±1.6毫升/分钟，p < 0.0001），近端横纹括约肌肌电图去极化幅度的平均增量更高（3.0±0.78对2.6±0.87毫伏，p = 0.02），而平均瞬时复极化缺失或显著降低（-0.3±0.61对0.3±0.9毫伏，p = 0.04）。形态学上，近端横纹括约肌萎缩，结缔组织增加。
尿道肌肉组织的结构和肌电图活动改变表明，新生期接触己烯雌酚使雄性大鼠易患尿道萎缩和协同失调，表现为近端横纹括约肌肌电图活动改变。
