On the nature of the socalled glycogenolytic fibers in the greater splanchnic nerves

Abstract

The hyperglycæmia which invariably results from interference with pulmonic ventilation, produced either by constriction of the air passages or by inadequacy of the respiratory movements, has led to the question whether or not the hyperglycæmia following stimulation of the great splanchnic nerves may not also be due to an asphyxial condition induced locally in the liver. Such a local asphyxia of the hepatic lobule might be the result of diminished blood supply caused by constriction of the blood vessels in Glisson's capsule, or by the diminution of portal blood supply following constriction of the splanchnic vessels.

The question, therefore, presents itself as to whether stimulation of the great splanchnic nerve causes hyperglycogenolysis because secretory nerve fibers influencing the production or activity of the glycogenolytic ferment in the liver are contained therein, or because of a local disturbance in the blood supply of the liver following stimulation of vaso-constrictor fibers.

In the following communication a preliminary report is offered of several experiments devised to throw some light on these problems.

1. All the tissues running to the hilus of the liver except the portal vein were cut between peripherally and centrally placed ligatures. As much as possible of the outer coat of the portal vein was also removed. By these three operations all the hepatic nerves running from the celiac plexus to the liver were severed. Stimulation of the great splanchnic nerve was found to cause no increase in the sugar content of the blood although the usual marked vaso-constriction of the splanchnic vessels occurred.

2. Clamping the portal vein for periods of about a minute at intervals of about two minutes, produces only in some cases an increase in the blood sugar.

3. Ligation of all branches of the hepatic artery running to the liver produces no change in the sugar content of the blood.