Urodynamic characteristics of awake rats under retrained versus freely moving condition: Using a novel model

Urodynamic investigation in conscious rats is widely employed to explore functional bladder disorders of various etiologies and pathogeneses. Rats can be placed in restraining cages or wide cabinets where they are allowed to move freely during cystometry. However, the requirements of special devices hampered the application of urodynamic test in freely moving rats, and whether the restraint has any effects on urodynamic parameters in conscious rats remains obscure. In the present study, we described a novel approach for urodynamic investigation in both restrained and freely moving conscious rats. In addition, we for the first time systematically compared the urodynamic parameters of rats in the two conditions. With the current method, we successfully recorded stable and repeatable intravesical pressure traces and collected expected reliable data, which supported the idea that the restraint does not affect the activity of the micturition reflex in rats, provided sufficient and appropriate measures could be applied during cystometry. Fewer technique problems were encountered during urodynamic examination in restrained rats than in freely moving ones. Taken together, conscious cystometry in rats placed in restraining cages with proper managements is a reliable and practical approach for evaluating the detrusor activity and bladder function.