Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, Mexico.
Neurourol Urodyn. 2014 Apr;33(4):455-60. doi: 10.1002/nau.22416. Epub 2013 May 1.
To evaluate the role of pelvic and perineal striated muscles on urethral function during micturition.
Pubococcygeus, or both bulbospongiosus and ischiocavernosus muscles were electrically stimulated during the voiding phase of micturition, and bladder and urethral pressure were simultaneously recorded in urethane anesthetized female rabbits. Bladder and urethral function were assessed measuring urodynamic and urethral pressure variables obtained before and during the stimulation of muscles. Two-tail paired t-tests were carried out in order to determine significant differences (P < 0.05) between groups.
Electric stimulation of the pubococcygeus during voiding decreased voiding efficiency and voided volume, whereas residual volume, the duration of voiding, the interval between bladder contraction and urethral resistance increased. Simultaneously, there was an increase in maximum urethral pressure, as well as an increase in the pressure to return to baseline and in the pressure required to close the urethra. Electrical stimulation of bulbospongiosus and ischiocavernosus muscles increased voiding efficiency, voiding duration, and the maximal pressure in bladder. Meanwhile, the maximal urethral pressure, the time related to the rise of urethral pressure, and the urethral pressure required to close the urethra decreased.
The stimulation of pelvic and perineal muscles have opposing roles in urethral function during micturition. Pubococcygeus muscles facilitate urethral closure, while they inhibit bladder contraction. In contrast, bulbospongiosus and ischiocavernosus muscles prevent urethral contraction while they promote bladder contraction.
评估盆底和会阴部横纹肌在排尿过程中对尿道功能的作用。
在雌性乌拉坦麻醉兔的排尿期对耻骨尾骨肌、球海绵体肌和坐骨海绵体肌进行电刺激，并同时记录膀胱和尿道压力。通过测量尿动力学和在肌肉刺激前后获得的尿道压力变量来评估膀胱和尿道功能。采用双尾配对 t 检验来确定组间的显著差异（P < 0.05）。
在排尿期间刺激耻骨尾骨肌可降低排尿效率和排尿量，而残余尿量、排尿持续时间、膀胱收缩与尿道阻力之间的间隔增加。同时，尿道最大压力增加，以及回到基线的压力和关闭尿道所需的压力增加。刺激球海绵体肌和坐骨海绵体肌可增加排尿效率、排尿持续时间和膀胱最大压力。同时，尿道最大压力、尿道压力上升的时间以及关闭尿道所需的压力降低。
盆底和会阴部肌肉在排尿过程中对尿道功能具有相反的作用。耻骨尾骨肌有助于尿道关闭，同时抑制膀胱收缩。相比之下，球海绵体肌和坐骨海绵体肌防止尿道收缩，同时促进膀胱收缩。
