New method of measuring uroflow in the rat bladder

Urodynamic evaluation of bladder function requires the simultaneous measurement of detrusor pressure and uroflow. Although the rat is a common animal model to study several bladder dysfunctions, including partial outlet obstruction, one of the major problems is that the bladder capacity has been too small for the measurement of uroflow. We have developed a new method of measuring uroflow in the rat that is sensitive at low bladder volumes. The method is based on the change in conductance of the gap between two silver electrodes in a measuring chamber as the chamber fills with saline during voiding. An AC voltage supply drives a current through the saline. As the saline level rises in the chamber the conductance increases, with a corresponding increase in current flow. A linear correlation between time rate of change of electrical current and fluid flow rate exists over a wide range of values and suggests that this new rat flowmeter is both accurate and reproducible. © 1992 Wiley‐Liss, Inc.