Effect Of Different Frequency And Intensity Pudendal Nerve Stimulation On Overactive Bladder In Rats

Objective: To investigate the effect of different frequency and intensity ofpudendal nerve stimulation on cyclophosphamide (CYP)-induced overactive bladder inrat models，and to provide experimental evidence for the clinical application ofpudendal nerve stimulation to treat overactive bladder.Methods: A total of84female Sprague-Dawley rats weighing180-220g were randomlydivided into control group, overactive bladder (OAB) group and stimulation group.According to different frequency, stimulation group was randomly divided into:5HZstimulation group,7HZ stimulation group,10HZ stimulation group,20HZ stimulationgroup,40HZ stimulation group. Cystometry testing of all groups includinginter-contraction interval, basal pressure, micturition voiding pressure and bladdercapacity was carried out, and statistical analysis was done.Results:1. Compared with control group，inter-contraction interval and bladdercapacity were decreased significantly(p<0.01), and basal pressure was increasedsignificantly (p<0.01)in OAB group. Micturition voiding pressure was no differencesbetween OAB group and normal group (p>0.05).2.Low frequency pudendal nerve stimulation (5HZ,7HZ,10HZ) cansignificantly increase the OAB bladder inter-contraction interval and bladdercapacity (p <0.01), decrease basal pressure (p<0.01); high frequency pudendalnerve stimulation (20HZ,40HZ) could significantly decrease the OAB bladderinter-contraction interval (p <0.05)， bladder capacity (p<0.01) and basalpressure (p <0.01). Different frequency pudendal nerve stimulation had no significanteffect on the OAB bladder micturition voiding pressure (p>0.05).3. Compared to0.8T,1T stimulation intensity,2T stimulation intensity causedgreater increase in the inter-contraction interval and bladder capacity of the OAB bladder (p <0.05) under low frequency pudenal nerve stimulation (5HZ,7HZ,10HZ);Compared to0.8T,2T stimulation intensity,1T stimulation intensity caused greaterdecrease in the inter-contraction interval and bladder capacity of the OABbladder (p<0.05) under high frequency pudenal nerve stimulation (5HZ,20HZ,40HZ).Different intensity pudendal nerve stimulation had no significanteffect on the OAB bladder micturition voiding pressure and basal pressure (p>0.05).Conclusion: Pudendal nerve stimulation elicits inhibitory and excitatory reflexesof overactive bladder that are mediated by multiple mechanisms, and that the evokedresponse is strongly dependent on the frequency and intensity of electrical stimulationof the afferent inputs. Low frequency pudendal nerve stimulation (5-10HZ) can increasethe inter-contraction interval and bladder capacity, decrease basal pressure in OAB rats,which inhibits cyclophosphamide-induced overactive bladder, and2T intensity has themaximum inhibition; High frequency pudendal nerve stimulation (20-40HZ) can excitethe bladder micturition reflex, which may be suitable for the treatment of acontractiledetrusor.