Glucose uptake of hepatocytes and pancreatic beta cells (in mice, but GLUT1 in human beta cells; see Reference 1). The high Km of GLUT2 allows for glucose sensing; rate of glucose entry is proportional to blood glucose levels. GLUT4 transporters are insulin sensitive, and are found in muscle and adipose tissue. As muscle is a principal storage site for glucose and adipose tissue for triglyceride (into which glucose can be converted for storage), GLUT4 is important in post-prandial uptake of excess glucose from the bloodstream. Moreover, several recent papers show that GLUT 4 is present in the brain also. The drug metformin
Stress in early childhood the skin and gut. This allows a sufficient amount of blood to access the brain and muscles. Also, epinephrine initiates the breakdown of glycogen in the liver, in turn increasing blood glucose levels. This energy source allows humans to enact defensive responses due to stress. In the human body, the steps that lead to the release of glucocorticoids such as cortisol begin with the release of corticotropin releasing hormone (CRH) and arginine vasopressin (AVP). These hormones travel through the blood vessels to the anterior pituitary gland of the brain. At this location, adrenocorticotropic hormone (ACTH) is released. ACTH binds to