Evidence for vasopressin production in the human gastrointestinal system

In the present study we performed immunohistochemical examination of segments from the human gastrointestinal system for the presence of cells containing vasopressin (VP) and vasopressin-associated human neurophysin (VP-HNP). VP immunoreactivity was found in crypt cells of the stomach and small intestine, and in mononuclear cells within the lamina propria and submucosa. VP-HNP was demonstrated in the crypt and lamina propria regions of the small intestine, and was colocalized with vasopressin in crypt cells. This colocalization indicates local vasopressin synthesis by these cells and raises the possibility that they may perform an endocrine or exocrine function in the human gastrointestinal system.