Gastrin is mainly known by its first described role as a gastric acid-hormone but the protein also has the ability to promote cellular growth. More recently, gastrin has been suggested to induce leukocyte-endothelial cell interactions and to have a pro-inflammatory effect. High levels of Gastrin Releasing Peptide (GRP) are found in the human lung just after birth and levels decrease thereafter in parallel with the observed disease in number of pulmonary neuroendocrine cells. GRP is known to promote lung tumorigenesis in model systems and, interestingly, is induced by retinoic acid. GRP is involved in several functions with the hypothalamus, and is thought to play a role in regulating pituitary hormone secretion.
