To clarify the lower urinary tract function in mice, we compared bladder and urethral activity between rats and mice with or without spinal cord injury (SCI). Female Sprague-Dawley rats and C57BL/6N mice were divided into five groups:1) spinal intact (SI) rats,2) SI mice,3) pudendal nerve transection (PNT) SI mice,4) spinal cord injury (SCI) rats, and 5) SCI mice. Continuous cystometry (CMG) and external urethral sphincter (EUS)-electromyogram (EMG) analyses were conducted under an awake, restrained condition. During voiding bladder contractions, SI animals exhibited EUS bursting with alternating active and silent periods, which, in rats but not mice, coincided with small-amplitude intravesical pressure oscillations in CMG recordings. In SI mice with bursting-like EUS activity, the duration of active periods was significantly shorter by 46% (32 ± 5 ms) compared with SI rats (59 ± 9 ms). In PNT-SI mice, there were no significant differences in any of cystometric parameters compared with SI mice. In SCI rats, fluid elimination from the urethra and the EUS bursting occurred during small-amplitude intravesical pressure oscillations. However, SCI mice did not exhibit clear EUS bursting activity or intravesical pressure oscillations but rather exhibited intermittent voiding with slow large-amplitude reductions in intravesical pressure, which occurred during periods of reduced EUS activity. These results indicate that EUS pumping activity is essential for generating efficient voiding in rats with or without spinal cord injury. However, EUS bursting activity is not required for efficient voiding in SI mice and does not reemerge in SCI mice in which inefficient voiding occurs during periods of reduced tonic EUS activity.

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Aim : To clarify the influence of hypertension on lower urinary tract symptoms (LUTS) we examined the relationship between blood pressure, LUTS, and the effect of terazosin on LUTS in patients with benign prostatic hyperplasia (BPH). Methods : The subjects were patients who had LUTS and BPH. They were treated with terazosin (1 mg, twice-a-day) for 12 weeks. Calculation of the International Prostate Symptom Score (IPSS), measurement of blood pressure, and uroflowmetry were performed before and after 12 weeks of therapy. Patients were divided into a normotensive (NT) group and a hypertensive (HT) group at the time of first examination. Results : The IPSS for urinary frequency and nocturia in BPH-HT patients ( n = 21; mean age, 71 years) were significantly higher than those in the BPH-NT patients ( n = 21; mean age, 69 years) before the administration of terazosin. The total IPSS the BPH-HT patients was also significantly higher than that of the BPH-NT patients. There were no differences of uroflowmetric parameters between the two groups. After 12 weeks of therapy, systolic and diastolic blood pressure decreased in the BPH-HT patients, but not in the BPH-NT patients. However, the systolic pressure of the BPH-HT patients was still significantly higher than that of the BPH-NT patients. The score for each IPSS parameter decreased in both groups, but the difference of the score between the two groups increased. Conclusion : Hypertension may worsen LUTS and may decrease the improvement of symptoms by terazosin.

We examined bladder and urethral sphincter activity in mice with or without spinal cord injury (SCI) after C-fiber afferent desensitization induced by capsaicin pretreatment and changes in electrophysiological properties of mouse bladder afferent neurons 4 wk after SCI. Female C57BL/6N mice were divided into four groups: ) spinal intact (SI)-control,) SI-capsaicin pretreatment (Cap), ) SCI-control, and) SCI-Cap groups. Continuous cystometry and external urethral sphincter (EUS)-electromyogram (EMG) were conducted under an awake condition. In the Cap groups, capsaicin (25, 50, or 100 mg/kg) was injected subcutaneously 4 days before the experiments. In the SI-Cap group, 100 mg/kg capsaicin pretreatment significantly increased bladder capacity and decreased the silent period duration of EUS/EMG compared with the SI-control group. In the SCI-Cap group, 50 and 100 mg/kg capsaicin pretreatment decreased the number of nonvoiding contractions (NVCs) and the duration of reduced EUS activity during voiding, respectively, compared with the SCI-control group. In SCI mice, hexamethonium, a ganglionic blocker, almost completely blocked NVCs, suggesting that they are of neurogenic origin. Patch-clamp recordings in capsaicin-sensitive bladder afferent neurons from SCI mice showed hyperexcitability, which was evidenced by decreased spike thresholds and increased firing rate compared with SI mice. These results indicate that capsaicin-sensitive C-fiber afferent pathways, which become hyperexcitable after SCI, can modulate bladder and urethral sphincter activity in awake SI and SCI mice. Detrusor overactivity as shown by NVCs in SCI mice is significantly but partially dependent on capsaicin-sensitive C-fiber afferents, whereas the EUS relaxation during voiding is enhanced by capsaicin-sensitive C-fiber bladder afferents in SI and SCI mice.

We compared the effects of melatonin, an antioxidant and sleep inducer in humans, and rilmazafone hydrochloride, a hypnotic, in elderly patients with nocturia. Patients received either melatonin (2 mg/day; n = 20) or rilmazafone (2 mg/day; n = 22) for 4 weeks. There were no significant differences in the mean age, the quality of life (QoL) score and the serum melatonin levels between the two groups at baseline. After 4 weeks' treatment, the number of nocturnal urinations was significantly decreased and the QoL score was significantly improved in both groups. There was no significant difference between the patient-reported effectiveness ratings between the two groups. The serum melatonin level was significantly increased in the melatonin-treated group, but it remained unchanged in the rilmazafone-treated group. Melatonin and rilmazafone were equally effective for nocturia in the elderly. We recommend that the problems of sleep disturbance should be considered when choosing a therapy for nocturia.