Glycogen synthase is an enzyme that stimulates your body to store glucose as glycogen. Your body runs primarily on glucose, using it to produce energy. In times of excess glucose, your body does not waste it. Instead, it bundles glucose molecules into a substance known as glycogen, which it can store within cells. Glycogen synthase is necessary for the production of glycogen. For diabetics, this can be a little complicated, as insulin is also necessary for glycogen storage.
Glycogen Synthesis
There are two scenarios in which your body triggers the production of glycogen. After you eat a meal, especially one high in carbohydrates, your blood glucose is high. As a response, insulin enters the bloodstream and facilitates the movement of glucose into cells as well as the production of glycogen. The second mechanism occurs during periods of extreme hunger or activity. Both of these cases can cause glycogen stores inside your cells to deplete, calling for refueling. Whatever the case, glycogen synthase is essential to the production of glycogen.
Insulin and the Liver
Insulin also acts on the liver. The liver is the main storage facility for excess glucose. When glucose levels increase in the blood, insulin triggers the liver cells to take in glucose, then it prompts the liver to increase glycogen stores. Insulin inhibits the enzyme, glucose 6 phosphotase, which is responsible for the breakdown of glycogen and at the same time, stimulates glycogen synthase inside the liver. This mechanism allows for a cache of glycogen stores that you may need for survival. Your body relies on these liver stores of glycogen during times of low blood glucose such as between meals, at night and during exercise.
Diabetes and Glycogen Synthase
Diabetes means you have a problem with your insulin mechanism. For those with type 2 diabetes, this usually means that your cells are unresponsive to the presence of insulin inside your blood. For this reason, the response to, and mechanism of, glycogen synthase is impaired. When your body does not respond to insulin or cannot produce insulin, glycogen synthase stimulation and glycogen stores also suffer.
Solution
The best course of action while living with diabetes is to keep your blood glucose in control. If you are on medications, take them, get regular exercise and control your diet. Exercise elicits an insulin-like effect on muscle cells. Glut-4 receptors on the outside of cells are prompted to take in glucose from the blood even without the presence of insulin. This response is due to the rhythmic contractions of exercise. In addition, exercise also increases glycogen stores over time.
References
- "Exercise Physiology"; George A. Brooks, Thomas D. Fahey, Kenneth M. Baldwin; 2005
- Colo State.edu; Physiologic Effects of Insulin; R. Bowen; August 2009
- "Diabetes"; Control of Glycogen Synthesis by Glucose, Glycogen, and Insulin in Cultured Human Muscle Cells; Reza Halse, et al.; 2001
- National Diabetes Information Clearinghouse: Diabetes Overview; November 2008
- Ex Rx.net: Glycogen
