Insulin

Insulin is produced in the beta cells of the pancreatic islets of Langerhans and is released into the circulation to act on specific cell-surface receptors. Its release is stimulated by rising blood glucose concentration and it is principally insulin which is responsible for the post-prandial gluconeogenesis observed in humans and dogs. Several hormones (including corticosteroids, progesterone, oestrogen, growth hormone, glucagon and catecholamines) have an antagonistic effect to insulin and cause the blood glucose concentration to increase. Interruptions at any stage in this pathway may produce the clinical syndrome of diabetes mellitus.