Satoshi Yotsuyanagi

Diagnostic value of intravesical lidocaine for overactive bladder

PURPOSE To determine the diagnostic use of intravesical lidocaine, we evaluated its effects on the overactive bladder in patients with brain lesions, spinal lesions, benign prostatic hyperplasia (BPH) and idiopathic overactive bladder. MATERIALS AND METHODS Cystometry was performed before and 15 minutes after intravesical instillation of 20 ml. 4% lidocaine in 57 patients with an overactive detrusor in the storage phase. RESULTS The percentage increase in bladder capacity for patients with spinal lesions was 136%, compared to 56%, 29% and 41% for patients with brain lesions, BPH and idiopathic bladder overactivity, respectively (significant difference p <0.01 to 0.05). Of the patients with an increase of 50% or more 55% had brain lesions, 80% spinal lesions, 23% BPH and 31% idiopathic bladder overactivity. The incidence of the disappearance of detrusor contractions in patients with spinal lesions was greater than that in the others. CONCLUSIONS These results suggest that intravesical instillation of 4% lidocaine is useful for identification of overactive bladder attributable to spinal or other lesions.

A causative factor of copulatory disorder in rats following social stress

PURPOSE We investigated the causative role of testosterone in copulatory disorder and the expression of c-fos messenger (m)RNA in the medial preoptic area in rats after social stress. MATERIALS AND METHODS To generate copulatory disorder rats in the experimental defeated group were attacked by residents for 10 minutes daily for 7 consecutive days (social stress). We then investigated the effect of repeat defeat on the frequency of mounting behavior and plasma testosterone levels. The effects of testosterone replacement and/or apomorphine (100 microg./kg. subcutaneously), a dopamine receptor agonist, on the frequency of mounting behavior were also studied. After experiencing social stress the brain area within the medial preoptic area was removed for analysis of c-fos and androgen receptor mRNA expression. Real-time reverse transcription-polymerase chain reaction was done to analyze gene expression. RESULTS Rats in the defeated group showed a reduced frequency of mounting behavior and a decrease in plasma testosterone levels compared with values in control rats (p <0.01). After testosterone replacement the frequency of mounting behavior became significantly higher than that of socially stressed rat (p <0.05) but did not achieve control levels. The frequency of mounting behavior by socially stressed rats after apomorphine treatment was significantly higher than that of vehicle treated rats (p <0.05) but the frequency produced by the combination of testosterone replacement and apomorphine injection did not achieve control levels. After the social stress experience c-fos mRNA expression was significantly increased compared with that in control rats (p <0.05). The expression of androgen receptor mRNA was not affected by social stress. Testosterone replacement significantly reduced the expression of c-fos mRNA in the medial preoptic area (p <0.05). CONCLUSIONS Our results indicate that a reduction in plasma testosterone may have a causative role in copulatory disorder induced by social stress. Changes in c-fos mRNA expression in the medial preoptic area correlated with copulatory disorder and, thus, they are suitable for monitoring that disorder.

CONTRIBUTION OF CEREBRAL NITRIC OXIDE TO BLADDER OVERACTIVITY AFTER CEREBRAL INFARCTION IN RATS

PURPOSE We investigated the contribution of cerebral nitric oxide to neurogenic voiding dysfunction after cerebral infarction. MATERIALS AND METHODS The left mid cerebral artery in female Sprague-Dawley rats was occluded with 4-zero monofilament nylon thread. Bladder activity was monitored during infusion cystometrography. Time or dose dependent effects of intracerebral ventricular administration of the nonselective nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), were investigated in conscious, sham operated and cerebral infarcted rats. The selective neuronal nitric oxide synthase inhibitor 1-(2-trifluoromethylphenyl) imidazole was also administered to determine the participation of nitric oxide synthase subtypes. Cross-sectional infarct area was measured and infarct volume was calculated 12 hours after mid cerebral artery occlusion. RESULTS Bladder capacity was reduced by 54% 30 minutes after mid cerebral artery occlusion. L-NAME significantly increased bladder capacity in a dose and time dependent manner in cerebral infarcted rats but had no effect on sham operated rats. L-NAME (50 microg./kg.) administered 3 or 5 hours after occlusion significantly increased bladder capacity. This effect of L-NAME was reversed by injecting 250 microg. L-arginine per rat, which alone did not produce any significant change in bladder capacity in cerebral infarcted rats. Administration of 1-(2-trifluoromethylphenyl) imidazole also significantly increased bladder capacity in these rats. On the other hand, 5 microg. of the nitric oxide donor FK-409 per rat reduced bladder capacity for 10 to 15 minutes. None of the drugs affected infarct volume. CONCLUSIONS These results indicate that supraspinal nitric oxide has an important role in bladder overactivity after cerebral infarction but it does not affect normal micturition in rats. This finding suggests a central mechanism sensitive to nitric oxide for bladder overactivity after cerebral infarction.

Forebrain muscarinic control of micturition reflex in rats

Functional contribution of the cholinergic pathway between the frontal cortex and basal nucleus of Meynert to micturition reflex was investigated. Male Wistar rats were subjected to bilateral lesion of the basal forebrain by ibotenic acid (IA) injection (7.5 microg/rat on each side) (BF rats). Phosphate buffered saline (PBS) was injected into control rats (sham operated rats; SO rats). Cystometrograms were obtained from conscious BF and SO rats 7-10 days after IA/PBS injection. Bladder capacity (BC) of BF rats was significantly smaller than that of SO rats (approximately 43.7%) and was accompanied by decrease in choline-acetyltransferase activity in the frontal cortices. Oxotremorine M, a muscarinic receptor agonist, increased BC in BF rats, while pirenzepine, an M1 muscarinic receptor antagonist, counteracted the effect of the oxotremorine M-induced increase in BC. Injection of oxotremorine M into the dorsal pontine tegmentum (DPT) reduced BC in BF and SO rats, while injection of pirenzepine had no effect on cystometrograms. These findings indicate that the M1 muscarinic receptor plays a part in the forebrain inhibitory mechanisms involved in the micturition reflex and that muscarinic receptor in the DPT contributes to excitatory control of micturition reflex.

Dehydroepiandrosterone Alleviates Copulatory Disorder Induced by Social Stress in Male Rats

INTRODUCTION Social stress induces sexual dysfunction and reduces serum testosterone (T) level in rats. Stressful events exert an influence on a variety of behaviors and physiology through hormonal changes. The mechanism of stress-induced sexual dysfunction is unknown. AIM To investigate the role of dehydroepiandrosterone (DHEA) in copulatory behavior induced by social stress in rats. METHODS Stress-induced male rats were subjected to social stress in which the males lived in a wire-mesh siege located in a colony of male and female rats and were exposed daily to a brief defeat by the colony of males for five consecutive days. After the stress period, copulatory behavior and serum concentrations of DHEA and T were measured. MAIN OUTCOME MEASURES The effects of DHEA, T, and NE-100, a selective sigma 1 receptor antagonist, on copulatory behavior following social stress were examined. RESULTS The males exhibited a marked suppression of copulatory behavior (elongation of intromission and ejaculation latencies). Serum concentrations of DHEA and T were significantly lower than those in nonstressed control males. Another three groups of social stressed males were injected daily with DHEA, T, or DHEA + NE-100 during the stress period. Injections of DHEA attenuated the stress-induced suppression of copulatory behavior, whereas T had no effect. The combined treatment of NE-100 made DHEA ineffective at restoring copulatory behavior. CONCLUSIONS These results indicate that DHEA, but not its conversion to T, alleviates the suppressive effect of social stress on copulatory behavior via sigma 1 receptors. We suggest that the decreased endogenous DHEA is involved in copulatory disorders induced by social stress in rats.

Expression of neural plasticity related gene in the pontine tegmental area of rats with overactive bladder after cerebral infarction.

PURPOSE We investigated the expression of the neural plasticity related genes c-fos, zif268, c-jun, brain-derived neurotrophic factor and tissue plasminogen activator in the pontine tegmental area in rats with overactive bladder induced by cerebral infarction. MATERIALS AND METHODS Cerebral infarction was induced by left middle cerebral artery occlusion in female Sprague-Dawley rats. Bladder activity was monitored by continuous infusion cystometrography in awake rats. Specimens were obtained from the pontine tegmental area 1, 3, 5, 12 and 24 hours after cerebral infarction or sham operation. The effect of 0.1 mg./kg. intravenously of the N-methyl-d-aspartate glutamatergic receptor antagonist MK-801 on bladder activity, and c-fos and zif268 expression after middle cerebral artery occlusion were studied. Real-time reverse transcriptase-polymerase chain reaction was performed with the LightCycler system (Roche Diagnostics, Mannheim, Germany) to evaluate cerebral infarction influences on gene expression in the pontine tegmental area. RESULTS Bladder capacity in cerebral infarcted rats was significantly reduced 1 to 24 hours after middle cerebral artery occlusion compared with that of sham operated rats (p <0.05 to 0.01). One hour after occlusion mean c-fos messenger (m)RNA expression plus or minus standard error had significantly increased to 18.9 +/- 4.0 in terms of its density relative to the outer control in a sample obtained immediately after occlusion compared with that in sham operated rats (p <0.05). It returned to the control level within 3 hours after occlusion. Mean zif268 mRNA expression significantly increased to a relative density of 3.2 +/- 1.4 3 hours after middle cerebral artery occlusion (p <0.01) and returned to the control level within 5 hours after occlusion. The expressions of c-jun, brain-derived neurotrophic factor and tissue plasminogen activator was not influenced by occlusion. Pretreatment with MK-801 inhibited bladder overactivity and significantly reduced the expression of c-fos and zif268 mRNA in the pontine tegmental area. CONCLUSIONS These results indicate that the development of bladder overactivity after middle cerebral artery occlusion is mediated by activation of an N-methyl-d-aspartate receptor and accompanied by an increase in c-fos and zif268 mRNA expression in the pontine tegmental area.

Mild Brain Ischemia Produces Bladder Hyperactivity without Brain Damage in Rats

Introduction: The influence of brain ischemia without cerebral infarction on voiding function is unknown. To investigate the effects of a reduction in cerebral blood flow on voiding function, the influence of chronic cerebral hypoperfusion (CH) on bladder activity was examined in rats. Materials and Methods: CH was induced in each of 11 female Sprague-Dawley rats by anastomosis between the right external jugular vein and the right common carotid artery with partial obstruction of the left common carotid artery. Twelve intact animals comprised a control group. Voided volume per micturition was assessed in a metabolic cage for 24 h on weeks 2, 4, and 8. Eight weeks after the operation, the rats were tested in a hippocampus-related learning paradigm, the Morris water maze. Bladder activity was monitored in 13 rats with continuous infusion cystometrography (CMG) at 2 weeks. After evaluation, the rats’ brains were stained by perfusion with 2% 2,3,5-triphenyltetrazolium chloride (TTC). Results: Voided volume per micturition was significantly reduced and voiding frequency was significantly increased in CH rats 2 weeks after CH as compared to the control group (p < 0.05). Bladder capacity on CMG of CH rats was significantly reduced 14 days after CH as compared to the controls (p < 0.05). Although TTC staining of the CH rat brain did not show cerebral infarction, CH induced impairment of water maze learning. Conclusions: These results indicate that mild forebrain ischemia without infarction results in the development of bladder hyperactivity and impairment of memory. Mild brain ischemia with aging may induce bladder overactivity in humans. Further studies of the nervous system related to bladder hyperactivity using this animal model may lead to pharmacological therapy or prevention of bladder overactivity in the aging individual with an unidentified origin of voiding dysfunction.

Overactive Bladder - Experimental Aspects

Supra-pontine lesions resulting from neurological disorders such as vascular disease, Parkinsons disease, or Alzheimer type senile dementia lead to an increase in bladder activity. This is due in part to the removal at the cortical inhibitory control of the micturition center in the brain stem - i.e. the pontine micturition center (PMC) - and in part to facilitation of excitatory control. These inhibitory or excitatory controls consist of several neurotransmitter systems, including glutamate, dopamine, n -aminobutyric acid (GABA), and acetylcholine. Bladder overactivity caused by cerebral infarction is mediated by upregulation of N-methyl-D-aspartate (NMDA) glutamatergic and D2 dopaminergic excitatory mechanisms, and by downregulation of NMDA glutamatergic and M1 muscarinic inhibitory mechanisms in the brain. Bladder overactivity associated with Parkinsons disease is reportedly induced by a loss of input to the D1 dopaminergic receptor. Furthermore, bladder overactivity caused by Alzheimer type dementia is thought to be mediated by downregulation of M1 muscarinic inhibitory mechanisms. Development of bladder overactivity following cerebral infarction is mediated by activation of the NMDA receptor and accompanied by an increase in c-fos, zif268 and COX-2 mRNA expression in the dorsal pontine tegmentum.

Stone Attenuation Values Measured by Average Hounsfield Units and Stone Volume as Predictors of Total Laser Energy Required During Ureteroscopic Lithotripsy Using Holmium:Yttrium-Aluminum-Garnet Lasers.

OBJECTIVE To evaluate the predictors of the total laser energy (TLE) required during ureteroscopic lithotripsy (URS) using the holmium:yttrium-aluminum-garnet (Ho:YAG) laser for a single ureteral stone. MATERIALS AND METHODS We retrospectively analyzed the data of 93 URS procedures performed for a single ureteral stone in our institution from November 2011 to September 2015. We evaluated the association between TLE and preoperative clinical data, such as age, sex, body mass index, and noncontrast computed tomographic findings, including stone laterality, location, maximum diameter, volume, stone attenuation values measured using average Hounsfield units (HUs), and presence of secondary signs (severe hydronephrosis, tissue rim sign, and perinephric stranding). RESULTS The mean maximum stone diameter, volume, and average HUs were 9.2 ± 3.8 mm, 283.2 ± 341.4 mm3, and 863 ± 297, respectively. The mean TLE and operative time were 2.93 ± 3.27 kJ and 59.1 ± 28.1 minutes, respectively. Maximum stone diameter, volume, average HUs, severe hydronephrosis, and tissue rim sign were significantly correlated with TLE (Spearmans rho analysis). Stepwise multiple linear regression analysis defining stone volume, average HUs, severe hydronephrosis, and tissue rim sign as explanatory variables showed that stone volume and average HUs were significant predictors of TLE (standardized coefficients of 0.565 and 0.320, respectively; adjusted R2 = 0.55, F = 54.7, P <.001). CONCLUSION Stone attenuation values measured by average HUs and stone volume were strong predictors of TLE during URS using Ho:YAG laser procedures.