Non-neuromuscular determinants of intraluminal urethral pressure in the female baboon: relative importance of vascular and nonvascular factors.

The female urethral sphincteric mechanism has both neuromuscular and non-neuromuscular components. The latter component has several determinants, including the urethral mucosa, the connective tissue of the urethra and periurethra, and the submucosal vascular bed. This study was designed to characterize the non-neuromuscular component of the urethral pressure profile (UPP) by quantitating the relative contributions of its vascular and non-vascular determinants in four female baboons. Following minimization of the smooth muscle and striated muscle determinants (the neuromuscular component) with halothane and pancuronium bromide, UPPs were performed before and after aortic occlusion. It is concluded that vascular and non-vascular factors contribute nearly equally to the non-neuromuscularly generated portion of intraluminal urethral pressure.