HUMAN INTESTINAL TREFOIL FACTOR IS EXPRESSED IN HUMAN HYPOTHALAMUS AND PITUITARY - EVIDENCE FOR A NOVEL NEUROPEPTIDE

Human intestinal trefoil factor, hITF, a secretory polypeptide found m ainly in the human gastrointestinal tract, is a member of the newly ch aracterized trefoil factor or P-domain peptide family representing put ative growth factors. Here we describe the identification of this gut peptide in the human brain and pituitary. With reverse transcriptase p olymerase chain reaction, we were able to isolate and clone the transc ript from human hypothalamus. An antibody generated against a syntheti c peptide derived from the carboxyl terminus of hITF was used for immu nohistochemical studies of appropriate tissue sections. Neurons expres sing hITF were identified in two magnocellular hypothalamic nuclei, th e paraventricular and periventricular nuclei. hITF polypeptide was als o observed in Herring bodies of the neurohypophysis and in secretory c ells of the adenohypophysis. Double immunostaining with antigrowth hor mone antibody showed partial coexistence in a selected subpopulation o f adenohypophysial cells. Localization of hITF in the hypothalamo-neur ohypophysial system may suggest a modulatory action on the classic al magnocellular nonapeptides vasopressin and oxytocin, and further indic ates an adenohypophysial importance of this peptide. It is likely that hITF represents a novel neuropeptide of yet unknown function.