The alleged discharge of the internal secretion of the pancreas into the lymph

Abstract

In 1898 Biedel 1 reported a “new form of experimental diabetes” by ligation of the thoracic duct and by establishing a fistula of the thoracic duct. These results were interpreted as proving that the internal secretion of the pancreas reaches the blood indirectly via the lymph of the thoracic duct, and led to attempts to modify or control diabetes by treatment with lymph from the thoracic duct, with contradictory and practically negative results. 1 In cases where we have adequate tests for the internal secretion of an organ (for example, the adrenal glands) it has been shown that these secretions pass directly into the blood, not into the lymph. Despite this, the view that the internal secretions are discharged primarily into the lymph appears to be an attractive one to many physiologists, as shown by the survival of this theory in the case of the thyroids, and the recent attempts to secure evidence for the theory in the case of the hypophysis.

It is not clear that the glycosuria reported by Biedl following interference with the thoracic lymph is true pancreatic diabetes. Ligation of the thoracic duct may cause a temporary hyperglycosuria owing to injury of the liver by the edema from the back pressure of the lymph. And the fistula experiments do not exclude a temporary glycosuria due to the operation and the anesthesia.

We have repeated the thoracic duct fistula experiment of Biedl in two dogs with negative results. We found it impossible to maintain a continuous flow of lymph with a cannula in the duct owing to clotting. We therefore ligatured the veins in such a way that the thoracic lymph discharged into the external jugular vein, and this vein was slit open and secured to the skin, thus allowing free escape of the lymph.