Leptin in the human stomach

Secretory granules of both endocrine and chief cells of the stomach contain leptin. It is probably secreted in the stomach lumen by chief cells and into the stomach circulation by a special type of endocrine cell. The observation that intravenous infusions of pentagastrin or secretin caused an increase in circulating leptin levels and leptin release into gastric juice is in keeping with both endocrine and exocrine secretory sources. They could function in the short term system to control feeding behaviour and in the gastrointestinal lumen to regulate the availability of nutrients acting in the sites where a non-degraded form of hormone would approach.There is a need for further investigation in humans, with difficulties arising from ethical limitations. However, we can conclude that three important pathways (endocrine, exocrine, and autocrine) for the action of leptin are present in human stomach, where the main physiological role for this hormone is foreseen.