ISOVOLUMETRIC BLADDER CONTRACTION

A MODEL FOR RHYTHMIC BLADDER CONTRACTIONS

Cystometry in anesthetized animals while the bladder is continually contracting and relaxing.

Filling of the bladder after acute urethral ligation activates pelvic afferent fibers which induces continuous rhythmic bladder contractions.

Rat, guinea-pig

•  This model is suitable for testing compounds for effects on the bladder reflex and is often used as a relatively high throughput in vivo model for screening compounds.
• Compounds producing effects in this model include those acting on afferent C-fibers such as TRPV1 and TRPM8 receptor antagonists, NK₁ antagonists and purinergic P2X₃ receptor antagonists, but also compounds acting on efferent nerves such as muscarinic antagonists.

• The ureters are ligated and transected. The bladder is initially emptied, the urethra ligated then the bladder is slowly filled with saline until rhythmic bladder contractions are induced.
• Test compounds can be administered intravenously (other routes may be possible depending on compound characteristics) and cystometric parameters evaluated for up to one hour post-administration.

• Frequency of bladder contractions
• Amplitude of bladder contractions
• Basal intravesical pressure

• Lluel P et al, Aspet-Ray Fuller Symposium, Lower Urinary Tract Disorders, July 6-7, 2002
• Yoshiyama M & de Groat WC, Am J Physiol 280: R1414-R1419, 2001
• Shimizu I et al, Eur J Pharmacol 412: 171-179, 2001
• Uchida M et al, J Pharmacol Sci 94: 122-128, 2004