Journal of Neurophysiology, Vol 68, Issue 5 1842-1849, Copyright © 1992 by APS
Role of sympathetic innervation in the feline continence process under natural filling conditions
C. W. Vaughan and P. M. Satchell
Gordon Craig Laboratory, Department of Surgery, University of Sydney, Australia.
1. The effect of the sympathetic innervation on the bladder detrusor muscle
was assessed in pentobarbitone-anesthetized cats by measuring the changes
in bladder wall tension that occurred during sympathetic ganglion blockade
after filling the bladder at a natural rate. 2. At a point 60% of the way
through the continence process, systemic sympathetic blockade was produced
by intravenous trimethaphan, and selective blockade of postganglionic
hypogastric nerve activity was produced by application of trimethaphan to
the exposed inferior mesenteric ganglia. The level of blockade was
monitored with an in-continuity hypogastric nerve recording. 3. During both
systemic and selective ganglion blockade, there was an increase in baseline
transmural bladder pressure and a decrease in the amplitude of
nonmicturating contractions. 4. Although there was no change in the mean
level of transmural bladder pressure during either systemic or selective
blockade, there was a significant increase in the mean level of bladder
wall mechanoreceptor discharge, suggesting that before the blockade
sympathoinhibitory effects were greater than sympathoexcitatory effects. 5.
Measurement of bladder wall mechanoreceptor discharge before and during
ganglion blockade revealed a net sympathoinhibitory influence on the level
of bladder wall tension under natural filling conditions. These results
confirm that the detrusor muscle of the feline bladder is under both
sympathoinhibitory and sympathoexcitatory influences for a significant
portion of the continence process.
