Hypogastric nerve section reveals a role for both afferent and efferent fibres in the feline continence process

Abstract

The role of the hypogastric afferent and efferent innervation in the process of urine storage during natural rate filling was examined in the pentobarbitone anaesthetized cat. The observed changes in bladder pressure following hypogastric nerve section demonstrated the presence of baseline sympatho-inhibitory and phasic sympatho-excitatory influences for a significant portion of each distension, which proceeded to a volume just over halfway through the continence process. A reduction in bladder wall compliance at the end of the distensions provided evidence for a net sympatho-inhibitory influence in the second half of the continence phase. Hypogastric nerve section also resulted in a reduction in the reflex increase in hypogastric efferent nerve activity, measured in-continuity. This suggested that hypogastric afferent fibres made a significant contribution to the regulation of sympathetic hypogastric nerve activity during natural rate filling.