F16357, a novel protease-activated receptor 1 antagonist, improves urodynamic parameters in a rat model of interstitial cystitis.
The aims of the present study were to characterize the role of PAR1 in rat bladder under inflammatory conditions and determine whether a selective PAR1 antagonist, F16357, can prevent the pathophysiological symptoms of cyclophosphamide-induced interstitial cystitis (IC).



Immunohistochemistry, contractile activity in isolated bladder and urodynamics were determined before and after cyclophosphamide treatment. F16357 was administered intravesically during the acute phase of inflammation, and effects on PAR1 and PAR1-related bladder contraction evaluated 24 h after cyclophosphamide injection. Urodynamics and associated voided volumes were recorded 7 and 24 h after cyclophosphamide.



In control conditions, PAR1 was present only in some umbrella cells. Cyclophosphamide disrupted the urothelium and expression of PAR1 by all remaining urothelial cells. After F16357 treatment, urothelial damage was absent and PAR1 immunoreactivity similar to control tissues. Thrombin and TFLLR-NH2 induced bladder contractions. These were increased in inflammatory conditions and antagonized by F16357 in a concentration-dependent manner. In telemetric experiments, furosemide increased urine production and voiding frequency for 60 min, 7 h after cyclophosphamide injection. Intravesical administration of F16357 blocked these changes with a return to a physiological profile; 24 h after cyclophosphamide, the volume of micturition was still lower with no increase in number of micturitions. F16357 30 μM reduced the number of micturitions and improved bladder capacity, but did not affect diuresis. Under similar experimental conditions, lidocaine 2% induced comparable effects.



PAR1 is expressed in rat bladder, overactivated in inflammatory conditions and involved in bladder function and sensation. F16357 could represent an interesting candidate for IC treatment.
Institut de Recherche Pierre Fabre, Castres, France.
N
N
Monjotin
Newcastle University, Newcastle upon Tyne, England.
J
J
Gillespie
Institut de Recherche Pierre Fabre, Castres, France.
M
M
Farrié
Institut de Recherche Pierre Fabre, Castres, France.
B
B
Le Grand
Institut de Recherche Pierre Fabre, Castres, France.
D
D
Junquero
IRSD, Université de Toulouse, INSERM, INRA, INP-ENVT, Université de Toulouse-3 Paul Sabatier, Toulouse, France.
N
N
Vergnolle
D000818:Animals; D018856:Cystitis, Interstitial / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D010879:Piperazines / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D044463:Receptor, PAR-1 / Q000378:metabolism; D010975:Platelet Aggregation Inhibitors
C000623380:F16357; D010879:Piperazines; D044463:Receptor, PAR-1; D010975:Platelet Aggregation Inhibitors