Response of the in vitro whole bladder (rabbit) preparation to autonomic agonists

Using an in vitro whole bladder preparation (rabbit), we studied both the volume-pressure relationship and the response of the bladder to specific autonomic agonists. We determined the response in: 1) an isovolumetric system in which the intravesical pressure was monitored in the absence of volume changes; 2) a system in which volume alterations were monitored in the presence of increasing pressure; and 3) a system in which the bladder emptied in the presence of a constant pressure. The results of these studies demonstrated: 1) volume-pressure studies generated a typical cystometric curve; 2) bethanechol produced a dose-dependent increase in intravesical pressure (decrease in bladder volume); 3) the whole bladder responded very poorly to isoproterenol; and 4) methoxamine and ATP both produced a modest increase in intravesical pressure. One advantage of the "whole bladder" in vitro preparation is that it can objectively measure a functional response of the bladder to pharmacological agents.