Experimental evidence for vasoactive intestinal peptide as the cause of the watery diarrhea syndrome.

We have infused pure porcine vasoactive intestinal peptide (VIP) into 8 healthy ambulant unsedated pigs. At plasma VIP levels closely comparable to those found in the human Verner-Morrison syndrome, gross watery diarrhea and hypokalemia were produced. When the VIP infusion was discontinued the water diarrhea ceased abruptly. This study therefore provides some evidence to implicate VIP as a possible causal agent in the pathogenesis of the human watery diarrhea syndrome.