Tibial nerve stimulation to inhibit the micturition reflex by an implantable wireless drivermicrostimulator in cats / 中华泌尿外科杂志

Objective Objective To evaluate the effects of a new type of tibial nerve microstimulator on the micturition reflex in cats.Methods From March to May in 2017,the implantable wireless driver micro-stimulator was implanted around the tibial nerve in 9 α-chloralose anesthetized domestic shorthairs cats (2.5-3.5 kg,6-12 months old).The stimulator was placed near the neurovascular bundle parallel to the tibial nerve and its cathode perpendicular to the cushion.The intensity which can induce toe movement was defined as threshold (T).The ureters were isolated via an abdominal incision.The ureters were cut and drained externally.The bladder was inserted via a double lumen catheter through the urethra.The catheter was then secured by a ligature around the urethra.One lumen of the catheter was used to infuse the bladder with either 0.9％ normal saline (NS) or 0.25％ AA at a rate of 1 to 2 ml/min after connecting to a pump.The other lumen was connected to a pressure transducer to measure the bladder pressure.The bladder capacity was used to test the inhibitory effect of the stimulator.After the appearance of the first large-amplitude (＞ 30 cmH2O) bladder contraction,the bladder infusion was stopped.First,after emptying the bladder,2 or 3 cystometrograms with NS were performed without stimulation to obtain the control bladder capacity.After the bladder was stabilized,TNS (6 Hz,1-2 T) was applied during 2 sequential cystometrograms.Second,after emptying the bladder,0.25 ％ AA was infused into the bladder to irritate and induce bladder overactivity.After the bladder stabilized,TNS (6 Hz,1-2 T) was applied again during 2-3 sequential cystometrograms.If bladder capacity increased significantly,the stimulationhad an inhibitory effect on the micturition reflex.Results During normal saline infusion,the bladder baseline was (17.03 ± 4.10) ml.TNS at 1T did not change the bladder capacity [(18.56 ±0.81)ml] (P ＞0.05).TNS at 2T significantly increased the bladder capacity [(25.05 ± 1.19) ml] (P ＜ 0.05).Compared to normal saline infusion,bladder overactivity was irritated by the intravesical infusion of 0.25％ acetic acid,which significantly reduced the bladder capacity [(9.34 ± 0.75) ml] (P ＜ 0.05).Compared to acetic acid infusion,TNS at 1T did not change the bladder capacity [(11.32 ± 0.82) ml] (P ＞ 0.05).TNS at 2T significantly increased the bladder capacity [(14.82 ± 1.15) ml] (P ＜ 0.05).Conclusions The implantable wireless driver tibial nerve micro-stimulator appears to be effective in inhibiting the micturition reflex during physiologic and pathologic conditions.The implantable wireless driver tibial nerve microstimulator was excepted to be used to treat overactive bladder (OAB).

Effect of Warming on Detrusor Muscle Contraction and the Micturition Reflex in Rats / 日本温泉気候物理医学会雑誌

Objectives: To investigate the effect of warming on contraction of the detrusor muscle and the micturition reflex in rats. Methods: Female Sprague-Dawley rats were used in this study. Changes in the contractile response of detrusor smooth muscle strips to 40 mM KCl caused by warming to 40°C and 42°C were evaluated by an isometric tension recording study. The effect of intravesical warming at 40.7±1.0°C on the micturition reflex was evaluated by continuous infusion cystometry in conscious rats. Results: Warming to 40°C and 42°C inhibited 40 mM KCl-induced contractions of detrusor smooth muscle strips by 10% and 15.5%, respectively. Intravesical warming at 40.7±1.0°C decreased the pressure threshold for inducing micturition by 14%, resting pressure by 30%, closing peak pressure by 22%, 2nd phase contraction duration by 36%, bladder contraction duration by 26%, and increased bladder compliance by 17%. Maximal voiding pressure and 1st phase contraction duration were unaltered. Conclusions: Our results demonstrated that warming relaxed the detrusor muscle and increased bladder compliance. This suggests that warming might be useful for treatment of low compliance bladder observed in the neurogenic bladder due to neurological diseases such as spinal cord injury. To clarify the usefulness of warming or hot springs for the treatment of neurogenic bladder, the effect of warming on the body surface on the micturition reflex should be investigated.

Effect of Warming on Detrusor Muscle Contraction and the Micturition Reflex in Rats / 日本温泉気候物理医学会雑誌

<b>Objectives:</b> To investigate the effect of warming on contraction of the detrusor muscle and the micturition reflex in rats.<BR><b>Methods:</b> Female Sprague-Dawley rats were used in this study. Changes in the contractile response of detrusor smooth muscle strips to 40 mM KCl caused by warming to 40°C and 42°C were evaluated by an isometric tension recording study. The effect of intravesical warming at 40.7±1.0°C on the micturition reflex was evaluated by continuous infusion cystometry in conscious rats.<BR><b>Results:</b> Warming to 40°C and 42°C inhibited 40 mM KCl-induced contractions of detrusor smooth muscle strips by 10% and 15.5%, respectively. Intravesical warming at 40.7±1.0°C decreased the pressure threshold for inducing micturition by 14%, resting pressure by 30%, closing peak pressure by 22%, 2nd phase contraction duration by 36%, bladder contraction duration by 26%, and increased bladder compliance by 17%. Maximal voiding pressure and 1st phase contraction duration were unaltered.<BR><b>Conclusions:</b> Our results demonstrated that warming relaxed the detrusor muscle and increased bladder compliance. This suggests that warming might be useful for treatment of low compliance bladder observed in the neurogenic bladder due to neurological diseases such as spinal cord injury. To clarify the usefulness of warming or hot springs for the treatment of neurogenic bladder, the effect of warming on the body surface on the micturition reflex should be investigated.

Changes of BDNF (Brain Derived Neurotrophic Factor) Expression Associated with Urodynamic Changes in Rat Spinal Cord Injury Animal Model / 대한해부학회지

Spinal cord injury results in dramatic changes in the neurochemistry of peripheral and central micturition reflex pathways. We studied an animal model of spinal cord contusion injury using Sprague Dawley rats. Recoveries of motor and bladder functions were recorded, along with the changes in brain-derived neurotrophic factor (BDNF) in regions rostral and caudal to the injury site. Results are as follows: 1. Motor functions examined by the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale were fully recovered 28 d after spinal cord injury. 2. Bladder functions, monitored urodynamically, changed from flaccid paralysis at 4 d after spinal cord injury to spastic paralysis at 14, 18, and 28 d. 3. BDNF immunoreactive neurons and glial cells were found in both gray and white matters of the normal spinal cord, and the numbers decreased gradually after spinal cord injury 4. BDNF enzyme linked immunosorbent assay (ELISA) results were almost the same as for immunohistochemistry, but the intensity of decrease was more prominent in the caudal than in the rostral regions. Distinguishing between the beneficial or detrimental effects of neurotrophic factors in the context of micturition reflexes or regenerative responses will be a challenge, but is essential to understanding the effects of therapies directed at blocking the effects of neuroactive compounds or neurotrophic factors.

Effect of spinal cord injury on urinary bladder spinal neural pathway: a retrograde transneuronal tracing study with Pseudorabies virus / 中国康复理论与实践

@# ObjectiveTo determine the effect of acute and chronic spinal cord injury (SCI) resulted from thoracic cord transection on the urinary bladder spinal neural pathway.Methods76 adult Sprague-Dawley rats were randomly divided into 4 groups, non-SCI, SCIa, SCIb and SCIc respectively. The non-SCI rats underwent no surgical procedure except Pseudorabies virus (PRV) tracer injection into the bladder tissue, while the rats of other groups were spinalized and given PRV injection at different time after SCI. Transcardiac perfusion fixation was done in appropriate survival periods after PRV injection. Then sections of dorsal root ganglion (DRG) and spinal cord were processed for visualization of virus by the Streptavidin-Peroxidase (SP) immunohistochemical procedure. All sections were measured with the Olympus Cue-2 image analysis system.ResultsThe bladder weights in SCIb and SCIc groups markedly increased (P<0.001). The time-ordered flow charts of PRV tracing were similar in the non-SCI rats and in the SCI rats. The cross-sectional area of the labeled DRG cell profiles increased significantly after SCI (P<0.001). The number of labeled cells in dorsal horn in L6 and S1 segments 3 days after PRV injection markedly increased in chronic SCI rats, and so did the number of labeled motor neurons 4 days post-injection. ConclusionThe acute and chronic SCI have little effect on the process of virus transneuronal transport below the level of lesion. Subsequent to chronic SCI, marked reorganization of the micturition reflex pathways occurs.

Effects of glutamate and its recepetors on micturition reflex / 医学研究生学报

Glutamate is one of the important neurotransmitters and participates in micturition reflex in the cerebral cortex,pons and spinal cord micturition center.Glutamate receptors include metabotropic and ionotropic and the latter again include NMDA and non-NMDA receptors.They all have different effects on micturition reflex.NMDA and non-NMDA receptors may interact on each other,and so may glutamate and other neurotransmitters in the central nervous system.

The Effect of Distension of Distal Colon and Rectum on Micturition Reflex in Rats / 대한비뇨기과학회지

PURPOSE: Bowel distention stimulates neuroreceptors inside bowel wall with resultant effect to the bladder activity via segmental spinal reflex. This work aimed to elucidate the effects of distal colon and rectum distension on the micturition reflex. MATERIALS AND METHODS: The experiments were performed on female Sprague Dawley rats anesthetized with intraperitoneal urethane (1.25g/kg), weighing 250-350g. Intravesical pressure was measured by a conventional pressure transducer. Isovolumetric bladder contractions were recorded during distension of the distal colon and rectum. The frequency of voiding contractions was calculated by counting the number of peaks/10mins. of observation and the mean amplitude of the contractions were recorded from the cystometrogram. During maximal distention of the bowel, changes of the micturition reflex were observed repeatedly after injection of acetylcholine, phenylephrine and adenosine triphosphate (ATP). RESULTS: The frequency and amplitude of micturition reflex decreased significantly compared to baseline during incremental distension of the rectum. whereas, frequency was increased and amplitude was decreased significantly during distension of the distal colon. The micturition reflex inhibited by distension of the rectum was restored by acetylcholine. CONCLUSIONS: The micturition reflex was inhibited by distension of the rectum and restored by acetylcholine. This result indicated that the inhibition of the micturition reflex caused by distension of the rectum is related to parasympathetic nerve activity. With this results, it may be suggested that the constipation or abdominal distension due to intestinal motility disorder are associated with voiding dysfunction clinically.

The Role of Spinal and Peripheral alpha1 Adrenoceptors in Micturition Reflex in Rats / 대한비뇨기과학회지

PURPOSE: The role of spinal alpha1 adrenoceptors in normal micturition reflex of rat has not been known clearly yet. The purpose of this study is to elucidate the role of alpha1 adrenoceptor both at the spinal and peripheral level in mediating the micturition reflex which is induced by bladder distension in normal anesthetized rat and to compare the effects of different alpha1 adrenoceptor antagonists against the micturition reflex. MATERIALS AND METHODS: Wtih eighty female Sprague-Dawley rats(200-250gm) anesthetized with urethane, continuous cystometry was done by infusion of saline at a rate of 0.5ml/min. The following drugs were injected into femoral artery(intraarterial, i.a.) and subarachnoid space(intrathecal, i.t.) at the level of L6-S1 spinal cord segment; phentolamine, prazosin, doxazosin and tamsulosin. Cystometric parameters were analyzed before and after the drug injections; basal pressure(BP), micturition pressure(MP), bladder capacity(BC), micturition volume(MV), frequency and residual volume(RV). RESULTS: After i.a. injections of prazosin, doxazosin and tamsulosin, MP was significantly decreased. Doxazosin(i.a.), markedly increased MV, BC and RV. MP was more inhibited by doxazosin than prazosin or tamsulosin injection intraarterially. After i.a. injection of phentolamine, decrease in MP and frequency but increase in MV and BC were noted. Phentolamine(i.t.) raised BP and abolished MR followed by overflow incontinence. Prazosin(i.t.) induced marked increases in MV. Tamsulosin(i.t.) caused significant decreases in frequency but increases in BC. CONCLUSIONS: At spinal level, antagonism of micturition reflex evoked by bladder distension was more prominent by phentolamine. Inhibition of micturition reflex with alpha1 adrenoceptor blockers were greater peripherally. With these results, it could be suggested that micturition reflex evoked by volume-induced bladder distension could be modulated through alpha1 adrenoceptors at both the spinal and peripheral level. In some selected cases, alpha1 adrenoceptor agonist or antagonist can be useful for the management of lower urinary tract dysfunction

Effects of Intrathecal Transmitters on the Pain-induced Micturition Reflex / 대한비뇨기과학회지

PURPOSE: Irritations or painful stimuli to the bladde: may alter voiding behaviorand this may be associated with dysfunction of periurethral muscles. In our study, recording of bladder and sphincter activity in response to intravesical irritants(acetic acid, capsaicin) was done and the effects of Intrathecal administration of transmitters(enkephalin, susbtance P and its antagonist, or calcitonin gene related peptide and its antagonist) was analyzed MATERIALS AND METHODS: Adult male Sprague-Dawley rats(400-500gm) were anesthetized with intraperitoneal urethane mixed with entobar. The left femoral artery and vein were cannulated for blood pressure monitoring and drug administration. A catheter(PE 50) was inserted into the bladder dome through a midline abdominal incision and bipolar electromyographic(EMG) needle electrodes were placed into the urethral sphincter. Peak contractile pressure and EMG activities were measured on a polygraph. Saline, acetic acid, or capsaicin was infused into the bladder at 50mu1/min and saline, enkephalin (ENK), substance P(SP) and its antagonist, or calcitonin gene related peptide (CGRP) and its antagonist was administered intrathecally. RESULTS: Each micturition cycle started with an increase in bladder pressure which triggered the contraction of the external urethral sphincter. Fast Fourier transform(FFT) analysis of the external sphincter EMG revealed a peak activity at 500Hz. The inteNal and duration of EIOG bursts were 38+/-2 msec and 92+/-10 msec respectively. The interval of bladder contraction was 809+/-23 sec. Intravesical acetic acid and capsaicin activated micturition reflex earlier than in control group and intrathecal ENK, SP antagonist, and CGRP antagonist attenuated the parameters in activated micturition reflex. CONCLUSIONS: Urethral sphincte EMG showed constant burst duration and interval in spite of the infusion of acetic acid or capsaicin. Intravesical acetic acid or capsaicin increased the peak amplitude of intravesical pressure, lowered voided volume, and shortened EMG spike duration and voiding interval significantly. Intrathecal injection of ENK, SP, SP antagonist, CGRP, and CGRP antagonist changed the parameters, especially the voiding interval, voiding duration and peak pressure of the bladder.