[Effects of highly selective dorsal rootlets rhizotomy on bladder function and penis erection in SD rats].

OBJECTIVE

To study the highly selective dorsal rhizotomy influence on bladder and penis erection function of SD rats.

METHODS

Forty mature male SD rats of clean grades, with weight range of 300-350 g were selected. Ten rats were chosen to do electrophysiology study on dorsal rootlets of L6 and S1 segment. Changes in intravesical pressure (IVP) and intracavernous pressure (ICP) were investigated to define main segments which conducted to bladder and corpus cavernosum. Thirty rats were divided into two groups (A and B) on average at random. In group A, we made highly selective dorsal rhizotomy on the fascicle of conduction bladder detrusor muscle. In group B, we made highly selective dorsal rhizotomy on the fascicle of conduction corpus cavernosum. Changes of IVP and ICP after rhizotomy were investigated and recorded.

RESULTS

The changes of IVP during electrostimulation were of no significant variation between L6 and S1 (P=0.972). With the changes of ICP during electrostimulation, S1 segment was of more significant variation than L6 segment, ΔICP of S1 was (13.05±8.41) cmH2O (1 cmH2O=0.098 kPa), while ΔICP of L6 was (6.88±2.76) cmH2O (P<0.01). There was no reasonable variation in IVP and ICP on the left and right dorsal rootlets of S1 segment (P was 0.623 and 0.828 respectively). In group A, there was significant variation in IVP, ΔIVP of before rhizotomy was (14.37±4.89) cmH2O, while after rhizotomy was (3.25±1.29) cmH2O (P<0.001) while no obvious variation in ICP (P=0.153) after highly selective rhizotomy on S1 dorsal rootlets. In group B, there was significant variation in ICP, ΔICP of before rhizotomy was (11.97±4.41) cmH2O, while after rhizotomy was (2.68±1.01) cmH2O (P<0.001), but no obvious variation in IVP (P=0.162) after highly selective rhizotomy on S1 dorsal rootlets.

CONCLUSION

SD rats' different rootlets of S1 dorsal rootlets can be distinguished by microanatomy and electrostimulation. The IVP and ICP had distinct changes after highly selective dorsal rhizotomy. It could provide an experimental support to treat spastic bladder after spinal cord injury and retain at maximum reflexible erection function in the clinic.