Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: September 10, 2005
Publication Date: N/A
Technical Abstract: Insulin is one of the most important hormones in the body, serving to regulate plasma glucose concentrations, production of alternative energy sources, and the ability of glucose to enter cells of the body. The brain, an obligate glucose user, requires a constant supply of glucose. In periods where plasma glucose is reduced, i.e. fasting, an organism will maintain a steady supply of glucose to the brain by stimulating the production and release of glucose stored as glycogen in the liver, inducing non-neural tissues to use endogenous energy reserves (i.e., free fatty acids), and restricting entry of glucose into neural tissue only. In contrast, when glucose concentrations are high, these conditions are reversed. Insulin is the principal regulatory agent of these processes where its presence allows for the systemic uptake and storage of glucose during periods of high plasma glucose concentrations.