Overview of AMPK function
The hydrolysis of ATP to ADP provides the energy that drives most of the processes associated with living cells. To maintain an adequate supply of ATP, cells need mechanisms to match supply with demand. AMPK is a key regulator of energy metabolism both at the cellular and whole organism level. AMPK is activated by metabolic stresses that either reduce the generation of cellular ATP (glucose deprivation, hypoxia, ischemia, metabolic poisons) or stimulate ATP consumption (physical activity/muscle contraction). Once activated, AMPK turns off anabolic systems that consume ATP and turns on catabolic processes that generates ATP. Thus, at a cellular level AMPK regulates both glucose and lipid metabolism. AMPK also governs whole body energy metabolism by regulating food intake through neural circuits in the hypothalamus. The delivery of nutrients and oxygen to the tissue requires an intact vascular system, consequently AMPK also affects vascular growth and function. Thus, AMPK activation may contribute to the beneficial metabolic and vascular effects of physical activity and caloric restriction, and drug-mediated AMPK activation may mimic these beneficial health effects.