Glucagon increases blood glucose level by stimulating glycogenolysis and gluconeogenesis in the liver. Hypoglycemia results from inhibition of glycogenolysis and gluconeogenesis. Glucagon generally elevates the concentration of glucose in the blood by promoting gluconeogenesis and glycogenolysis. The aldolase used in gluconeogenesis and glycolysis is a cytoplasmic protein. Therefore, biotin is essential for amino acid catabolism, gluconeogenesis, and fatty acid metabolism. Alanine and lactate are major gluconeogenic precursors that enter gluconeogenesis as pyruvate. At this time, there is an up-regulation of glycogenolysis, gluconeogenesis, lipolysis, and ketogenesis. Metformin has been shown to indirectly affect pyruvate kinase through the inhibition of gluconeogenesis. Paradoxically, cortisol promotes not only gluconeogenesis in the liver, but also glycogenesis. Please note however that lipolysis releases glycerol which can enter the pathway of gluconeogenesis. Lactic acidosis arises from impairment of gluconeogenesis. Here other transaminases regenerate pyruvate, which provides a valuable precursor for gluconeogenesis. Muscular lactate enters the liver through the bloodstream in mammals, where gluconeogenesis occurs (Cori cycle). Ultimately, it decreases gluconeogenesis (glucose production) in the liver. This accumulation has downstream effects on gluconeogenesis and regeneration of adenosine triphosphate (ATP).