Study on the neurophysiologic of detrusor overactivity due to partial bladder outflow obstruction / 中华外科杂志

<p><b>OBJECTIVE</b>To study the neurophysiologic of detrusor overactivity (DO) due to partial bladder outflow obstruction (PBOO).</p><p><b>METHODS</b>Twenty four female Wistar rats with DO caused by PBOO were studied simultaneously with ten sham-operated rats. An electrophysiological multi-channel simultaneous recording system was used to record pelvic afferent fiber potentials as well as the pudendal nerve motor branch potentials, external urethral sphincter electromyogram (EUS EMG) and abdominal muscle EMG during filling cystometry. To test the effect of the unstable contraction in DO rats after the decentralization of the central nervous system, DO rats were studied the changes of the unstable contraction after transection of the spinal cord (T(8) level), pelvic nerve, the sympathetic trunk, and the pudendal nerve.</p><p><b>RESULTS</b>The incidence of DO was 62.5% in filling cystometry. During filling cystometry, there are two type of DO contraction according to the changes of pelvic afferent fiber signals, the relevant nerves and muscles responses: the small pressure of the unstable contraction (S-DO) and the big pressure of the unstable contraction (B-DO). For the B-DO, there were significant changes in the recordings of pelvic afferent fiber, the motor branch of the pudendal nerve, EUS EMG, and abdominal muscle EMG. While all these differences have not been recorded during S-DO. Both the filling-voiding cycle and the unstable contraction of B-DO were eliminated and the base line of bladder pressure increased after T(8) spinal cord transection. While the S-DO was not affected by such transection. When bladder relevant nerves were transected by the sequence of the pelvic nerve, the sympathetic trunk, and the pudendal nerve, the filling-voiding cycle was eliminated. The base line of bladder pressure increased significantly. No B-DO was recorded, but the S-DO still existed.</p><p><b>CONCLUSION</b>There are some bladder-genic factors take part in the DO contractions induced by PBOO.</p>

Morphological study on the role of ICC-like cells in detrusor neuro-modulation of rat urinary bladder / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the role of ICC-like cells in bladder neuromodulation in rat urinary bladder.</p><p><b>METHODS</b>14 SD rats and 1 guinea pig were sacrificed in this study. The ultra structural relationships among interstitial cells, nerves and detrusor smooth muscle cells (DSMCs) of urinary bladder were investigated by transmission electron microscopy (TEM). c-kit immunofluorescence was used to identify ICC-like cells in SD rat urinary bladder and the structural relationship between ICC-like cells and nerve terminals was studied by immunofluorescence (double-label).</p><p><b>RESULTS</b>Gap junction between ICC-like cells and DSMCs was confirmed by TEM. ICC-like cells were very close apposition with nerve terminals under TEM. ICC-like cells were identified to exist in sub-urothelium layer, along the longitude of smooth muscle bundles and among detrusor smooth muscle in SD rat urinary bladder by c-kit immunofluorescence. Double-labeled tissue with c-kit and PGP9.5 antibodies also showed that ICC-like cells were very close apposition with nerve terminals in SD rat bladder.</p><p><b>CONCLUSIONS</b>Morphological study indicated that ICC-like cells in rat urinary bladder may play an important role in detrusor neuromodulation. Further study on function will be helpful for elucidating the mechanism of bladder neuromodulation clearly.</p>