RELEASE OF GLP-1 FROM BODY

A model of the L-cell showing different triggering and amplifying pathways. Entry of glucose or amino acids via Na+-coupled transporters, presumably at least partially across the apical microvilli, combines with metabolic signals and other depolarizing signals to trigger membrane depolarization ( ) and the opening of voltage-gated Ca2+ channels. The consequent elevated Ca2+ concentration stimulates secretion of GLP-1. Hormonal and other nutritional signals enhance secretion downstream of membrane depolarization by, e.g., increasing cAMP production or triggering Ca2+ release from intracellular stores.