BIOSYNTHESIS OF VASOPRESSIN BY GASTROINTESTINAL CELLS OF BRATTLEBORO AND LONG-EVANS RATS

The distribution of vasopressin, provasopressin, vasopressin-associate d neurophysin, and vasopressin-associated glycopeptide was determined immunohistochemically in the gastrointestinal system of Brattleboro an d Long-Evans rats. Cells containing immunoreactivity for vasopressin, provasopressin, neurophysin, and glycopeptide were detected in the sam e cell types of the stomach and duodenum, while selected cells in the duodenum contained only immunoreactive glycopeptide. Unlike that in th e hypothalamus, staining for neurophysin in the gastrointestinal tract was sensitive to fixation. These findings indicate that vasopressin i s produced by cells in the rat gastrointestinal system and suggest the existence of synthetic pathways different from those found in hypotha lamic neurons.