Evaluation of surgical denervation of the liver in cats.

Bilateral carotid arterial occlusion was used as a means of reflexly activating hepatic sympathetic nerves in cats anesthetized with pentobarbital. The resultant hepatic arterial constriction was used as an index of effective surgical denervation of the liver in situations where the hepatic arterial blood pressure was held constant or was allowed to rise parallel with the systemic blood pressure. Cutting the anterior nerve plexus (around the common hepatic artery) produced a highly variable but incomplete reduction in the constrictor response to carotid occlusion. The remainder of the constrictor effect was abolished only when the posterior plexus and hepatic ligament were also cut. Thus, vascular resistance in the hepatic artery is controlled by both the anterior and posterior hepatic plexuses but the contribution of each plexus varies considerably from animal to animal. This must be considered in any experiments that use, or have used, denervation or stimulation of the hepatic nerves.