THE EFFECT OF INJECTED INSULIN ON THE STORAGE OF GLYCOGEN IN THE PANCREAS AND LIVER

¹ The Department of Physiology, McGill University, Montreal, Canada

1. In dogs, anæsthetized with amytal, nembutal, or chloralose, and in dogs whose spinal cord has been sectioned, the concentration of glycogen in the pancreas varies between 0·10 g. and 0·30 g. per 100 g. of gland.

2. Fasting does not diminish the concentration of the pancreatic glycogen unless prolonged for 36 hours or more.

3. Continuous intravenous administration of dextrose increases the concentration of the pancreatic glycogen at a rate which bears a definite relation to the amount of dextrose injected per kilogram body-weight per hour.

4. The administration of insulin retards glycogenesis in the pancreas.

5. The injection of dextrose alone readily increases the storage of hepatic glycogen.

6. The injection of dextrose along with insulin will increase the glycogen in the liver only if sufficient sugar is administered to prevent hypoglycæmia.

7. Since the administration of insulin has been found to increase the deposition of glycogen in the muscles, it is concluded that injected insulin has primarily a peripheral point of attack, and that it retards glycogenesis in the pancreas by increasing the uptake of glucose by the muscles.

The expenses of this research were defrayed by a grant obtained from the Banting Research Foundation, whose assistance is gratefully acknowledged.

The writer wishes to express her sincere appreciation of the helpful advice and encouragement which she has received from Dr. B. P. Babkin, under whose direction the investigation was carried out. She is indebted to Miss J. F. Oswald for help in the preparation of this manuscript for press.