Liver gluconeogenesis process (null)

The liver gluconeogenesis process is a metabolic pathway primarily occurring in hepatocytes that synthesizes glucose from non-carbohydrate precursors such as lactate, alanine, glycerol, and glucogenic amino acids, essential for maintaining blood glucose levels during fasting or starvation when glycogen stores are depleted. It involves eleven enzyme-catalyzed reactions, bypassing irreversible glycolysis steps via unique enzymes including pyruvate carboxylase, phosphoenolpyruvate carboxykinase (PEPCK), fructose-1,6-bisphosphatase (FBPase), and glucose-6-phosphatase (G6Pase), with the process being highly energy-demanding and requiring ATP/GTP hydrolysis. Regulation occurs at multiple levels: hormonally by glucagon (stimulates via cAMP/PKA/CREB), glucocorticoids, and thyroid hormones promoting key enzyme expression, countered by insulin suppressing via PI3K/Akt/FoxO1 inhibition; transcription factors like PGC-1α, CREB, and FoxO1 drive gluconeogenic gene transcription during fasting. In disease, dysregulated hepatic gluconeogenesis contributes to hyperglycemia in type 2 diabetes and metabolic disorders, where excessive glucose output persists despite high blood sugar. Drugs targeting this process, such as metformin (activates AMPK to inhibit gluconeogenesis) and GLP-1 agonists, reduce glucose production for diabetes therapy, though challenges include balancing inhibition to avoid hypoglycemia or acidosis. Primarily liver-based but also active in kidney and intestine, it integrates with Cori and Cahill cycles for substrate recycling from muscle and adipose tissue.

Other names

Gluconeogenesis (hepatic)hepatic gluconeogenesisde novo glucose synthesis (liver)

Inhibition of key enzymes (e.g., PEPCK, FBPase, G6Pase); Suppression of transcription factors (e.g., CREB, FoxO1, PGC-1α); Activation of insulin signaling pathways (PI3K/Akt)