In vivo cystometrogram studies in urethane-anesthetized and conscious guinea pigs.
Urinary bladder cystometry using urethral catheters is described in vivo in a urethane-anesthetized guinea pig preparation and compared to an awake-animal preparation in which surgically implanted catheters were used. Anticholinergic drugs dose-dependently inhibited the peak intravesical pressure (PvesP) to a maximum of approximately 80% but had no effect on other cystometrogram (CMG) parameters (threshold pressure, bladder capacity). Stereoselectivity was evident; dexetimide but not levetimide potently depressed PvesP. Oxybutynin was equipotent (ID50 approximately 0.15 mg/kg) in both preparations and showed a similar duration of action (t1/2 = 48-53 min). The data suggests that CMG parameters and the effects of oxybutynin were not affected by urethane anesthesia, making the in vivo urethane-anesthetized guinea pig preparation a valuable tool to evaluate both the filling and voiding phases of cystometry.
Peterson
J S
JS
Nova Pharmaceutical Corporation, Baltimore, MD 21224-2788.
Hanson
R C
RC
Noronha-Blob
L
L
D000758:Anesthesia; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D003558:Cystoscopy; D005260:Female; D006168:Guinea Pigs; D008333:Mandelic Acids / Q000494:pharmacology; D010276:Parasympatholytics / Q000494:pharmacology; D013237:Stereoisomerism; D014520:Urethane; D001743:Urinary Bladder / Q000033:anatomy & histology* / Q000187:drug effects
D008333:Mandelic Acids; D010276:Parasympatholytics; D014520:Urethane; D001285:Atropine; C005419:oxybutynin