Loxoprofen inhibits facilitated micturition reflex induced by acetic acid urinary bladder infusion of the rats

Effect of photobiomodulation on lower urinary tract dysfunction in rat cystitis model

OBJECTIVE

Photobiomodulation selectively controls the activity of the sensory nervous system associated with A-delta and C fibers. Hypersensitivity involving the afferent A-delta and C fibers occurs in cystitis and decreases urinary function. This study aimed to investigate the effect of photobiomodulation on urinary storage dysfunction and voiding functions in cystitis model rats.

METHODS

We prepared the rat cystitis model. Under anesthesia, a cannula was connected to the bladder via a ventral incision. 0.3% acetic acid or saline was injected into the bladder. Continuous cystometry was performed, measuring bladder pressure and voiding urine volume with rats freely mobile. Laser irradiation was applied to the L6 lumbosacral intervertebral foramen using an 830 nm laser. Residual urine was extracted post-cystometry.

RESULTS

In the rat cystitis model groups, there was a significant decrease in the voiding interval and volume compared to the group receiving normal saline infusion. After sham or laser irradiation, only the group with laser irradiation showed a significant increase in voiding interval (217%, p = 0.0002) and voiding volume (192%, p = 0.0012) in the parameters of storage dysfunction. The basal pressure, intravesical pressure, and residual urine volume remained unchanged in all groups before and after irradiation.

CONCLUSIONS

This study indicates that photobiomodulation may improve urine storage dysfunction without exacerbating voiding function in a rat model of cystitis. Thus, photobiomodulation may be a new treatment option for the hypersensitivity and detrusor overactivity caused by cystitis.

Synergistic effects of loxoprofen and glycine on the micturition reflex in conscious rats

We examined the inhibitory effects of loxoprofen, a cyclooxygenase inhibitor, and glycine, a major inhibitory neurotransmitter, on the micturition reflex in conscious rats and hypothesized that these drugs would interact synergistically to inhibit micturition. Voiding behaviors were assessed using a metabolic cage. Oral loxoprofen decreased the urinary frequency, and only a high dose(10 mg/kg) significantly reduced the voided volume. With cystometry, intravenous loxoprofen(0.1-3 mg/kg) and glycine (30 and 100 mg/kg) prolonged the intercontraction intervals (ICI) in adose-dependent manner, but did not change the maximum voiding pressure (MVP) in conscious rats. The combination of loxoprofen (3 mg/kg) and glycine (100 mg/kg) strongly prolonged the ICI more than with either drug alone. The lowest dose of loxoprofen (0.1 mg/kg) and glycine(30 mg/kg) did not affect either the ICI or the MVP, but their combination resulted in a significant increase in the ICI. These results suggest that the combined administration of loxoprofen and glycine produced a synergistic inhibitory effect on the micturition reflex.

Prostaglandin facilitates afferent nerve activity via EP1 receptors during urinary bladder inflammation in rats

We examined the effects of loxoprofen, a cyclooxygenase inhibitor, and ONO-8711, an EP1-receptor antagonist, on afferent nerve activity during acetic acid (AA, 0.1% v/v)-induced inflammation of the rat urinary bladder. Distension stimulation was performed (vesical pressure of 30 cm H2O) for 2 min. The neuronal discharge was recorded from L6 dorsal root filaments. The discharge was observed just after the beginning of distension and increased gradually thereafter. When the vesical pressure returned to control value, the discharge diminished abruptly. AA infusion increased the total number of spikes to 198 +/- 38.8% of control values. AA infusion also produced asynchronous discharge in 39% of the animals. Loxoprofen administration (1 mg/kg, i.v.) reduced the number of spikes to 40.3 +/- 14.8% of control values. ONO-8711 administration (1 and 3 mg/kg, i.v.) reduced the number of spikes to 81.6 +/- 1.6% and 32.2 +/- 7.4% of control values, respectively. These data indicate that loxoprofen or EP1-receptor antagonist inhibit the inflammation-related neuronal activity. EP1 receptors in the peripheral afferent nerve terminal and/or urothelium may facilitate the primary afferent nerve activity, which elicits the inflammation-induced micturition reflex.

Effectiveness of an anti-inflammatory drug, loxoprofen, for patients with nocturia

AIM

There is increasing evidence that non-steroidal anti-inflammatory drugs are effective for the treatment of nocturia. In this study, we attempted to investigate the role of loxoprofen sodium (loxoprofen) in the therapeutic management of patients with nocturia.

METHODS

Fifteen benign protastatic hyperplasia and/or overactive bladder patients (13 males and 2 females, 71.1 +/- 1.5 years old) with three or more voids per night were involved. These patients had received standard drug therapy. Although these patients had received standard drug therapy for more than half a year, they had still three or more episodes of nocturia. The patients took a single dose of 60 mg of loxoprofen at night prior to sleep. Before and 1 week after the initiation of this therapy, the effects of this treatment were assessed by frequency volume chart and a questionnaire.

RESULTS

In the questionnaire, seven patients answered as excellent, six patients demonstrated improvement of their symptoms, two patients did not show a significant change in their symptoms and no patients demonstrated a deterioration in the symptoms. In frequency volume chart, total void per day, total void per night, total urine volume per day, total night urine volume per day and single voided volume in the night before and after this treatment were 9.97 +/- 0.81 and 8.99 +/- 0.74 per day, 3.82 +/- 0.25 and 1.82 +/- 0.27 per night, 1349 +/- 81 and 1258 +/- 91 mL per day, 567 +/- 46 and 325 +/- 51 mL per night, and 143 +/- 13 and 149 +/- 10 mL, respectively.

CONCLUSION

Loxoprofen can be effective and useful for patients with nocturia. Our data suggest that the main mechanism of this effect is to decrease urine production during a night's sleep.