Rate of Emptying of Biliary Tract Following Section of Vagi or of All Extrinsic Nerves. ∗

Abstract

Previous experiments have demonstrated that section of the specific nerves to the choledochoduodenal junction in the cat so retards emptying of the gall bladder that double the time is required to empty half its contents after a meal of egg-yolk. Subdiaphragmatic section of the left vagus has approximately the same effect but when the right vagus is cut the time is tripled. Section of all splanchnics produces little change. 1 The evidence suggests that severance of the right vagus removes not only the fibers which activate the gall bladder but those which release the sphincter of Oddi by inhibiting the local nerve net that maintains its tonus between meals.

Surprisingly, a continuation of these experiments has shown that severance of both vagi, or complete denervation of the biliary tract (vagi and splanchnics), has no retarding effect on the rate of emptying, i.e., gall bladder and sphincter respond to hormone- producing food at least as fast as in the controls.

Since it is known that section of one vagus does not affect the rate of emptying of the stomach 2 but that section of both vagi relaxes the pyloric sphincter and decreases the initial time required for passage of food into the duodenum, 3 the rate of emptying of the denervated biliary tract may be explained on the basis that loss of vagus effect on the biliary musculature is compensated for by increased hormonal action resulting from faster discharge of hormone-producing food into the duodenum. Contrary to some earlier reports on section of nerves to the intestine 4 it can be stated that severance of all extrinsic nerves to the sphincter of Oddi, although resulting in destruction of preganglionic fibers, does not cause degeneration of the ganglion cells and postganglionic fibers (Fig. 1 C).