Effects of sensory neuron-specific receptor agonist on bladder function in a rat model of cystitis induced by cyclophosphamide.
OBJECTIVE
To investigate the effects of activation of sensory neuron-specific receptors (SNSRs) on cyclophosphamide (CYP) bladder overactivity in rats.


METHODS
Female Sprague-Dawley rats (235-258 g) were used. Rats were injected with either CYP (200 mg/kg, intraperitoneally) or saline (control). Continuous cystometrograms (0.04 ml/min) were recorded 48 h after CYP or saline injection under urethane anesthesia. After stable micturition cycles were established, a selective rat SNSR1 agonist, bovine adrenal medulla 8-22 (BAM8-22), was administered intravenously or intrathecally.


RESULTS
Cyclophosphamide treatment-induced higher baseline pressure and shorter intercontraction intervals compared with the control group. Intravenous administration of BAM8-22 at 10, 30 and 100 μg/kg significantly increased intercontraction intervals in the CYP-treated group. Intrathecal administration of BAM8-22 at 0.03, 0.1 and 0.3 μg also significantly increased intercontraction intervals in the CYP-treated group. Intravenous or intrathecal administration of BAM8-22 did not change baseline pressure or maximum voiding pressure in the CYP-treated group.


CONCLUSIONS
These findings indicate that activation of SNSRs can suppress CYP-induced bladder overactivity, probably due to suppression of bladder afferent activity.
Department of Urology, Tottori University Faculty of Medicine, 36-1 Nishi, Yonago, 683-8504, Japan.
Masashi
M
Honda
Naoki
N
Yoshimura
Bunya
B
Kawamoto
Naoto
N
Kobayashi
Katsuya
K
Hikita
Kuniyasu
K
Muraoka
Motoaki
M
Saito
Takehiro
T
Sejima
Michael B
MB
Chancellor
Atsushi
A
Takenaka
D000818:Animals; D003520:Cyclophosphamide / Q000633:toxicity*; D003556:Cystitis / Q000139:chemically induced* / Q000188:drug therapy*; D004195:Disease Models, Animal; D005260:Female; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D010446:Peptide Fragments; C571042:bovine adrenal medulla 8-22; D003520:Cyclophosphamide