Beneficial effects of suplatast tosilate (IPD-1151T) in a rat cystitis model induced by intravesical hydrochloric acid.
OBJECTIVE
To examine the effects of suplatast tosilate (IPD-1151T), a Th2 cytokine inhibitor recently recognized to improve the symptoms in patients with interstitial cystitis (IC), in a rat model of HCl-induced chronic cystitis, to elucidate the possible mechanisms by which the drug improves the symptoms of IC.


METHODS
Chronic cystitis was induced by intravesical instillation of 0.2 mL of 0.4 m HCl in female adult rats. After a once-daily oral administration of IPD-1151T (0.1-100 mg/kg) or prednisolone (5 mg/kg) for 7 days, cystometry was performed under urethane anaesthesia. The bladder from HCl-induced cystitis rats was also assessed histopathologically.


RESULTS
On cystometrography there was frequent voiding in cystitis rats. Administration of IPD-1151T for 7 days after intravesical HCl instillation dose-dependently increased the micturition volume and intercontraction intervals. Treatment with prednisolone had similar therapeutic effects. Histological analyses in the bladder from cystitis rats revealed oedema and infiltration of inflammatory cells such as mast cells and eosinophils in the lamina propria and the transitional epithelial thickening. These histological changes and the number of mast cells and eosinophils were reduced by administration of IPD-1151T or prednisolone.


CONCLUSIONS
The present results indicate that IPD-1151T improves bladder function and pathological changes in HCl-induced cystitis rats, as previously observed in patients with IC. The rat cystitis model induced by HCl could provide useful information for studying proposed therapies for IC which might involve T cell-dependent inflammatory responses as one of its potential pathophysiologies.
Kirimoto
Tsukasa
T
Taiho Pharmaceutical Co., Ltd, Tokushima Research Center, Optimal Medication Research Laboratory, Tokushima, Japan. t-kirimoto@taiho.co.jp
Nakano
Koushi
K
Irimura
Kenji
K
Hayashi
Yukio
Y
Matsuura
Naosuke
N
Kiniwa
Mamoru
M
Oka
Toshinori
T
Yoshimura
Naoki
N
D000818:Animals; D018926:Anti-Allergic Agents / Q000627:therapeutic use*; D001190:Arylsulfonates / Q000627:therapeutic use*; D018856:Cystitis, Interstitial / Q000188:drug therapy* / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D051381:Rats; D017207:Rats, Sprague-Dawley; D013452:Sulfonium Compounds / Q000627:therapeutic use*; D013601:T-Lymphocytes / Q000473:pathology; D016896:Treatment Outcome
D018926:Anti-Allergic Agents; D001190:Arylsulfonates; D013452:Sulfonium Compounds; C073028:suplatast tosilate