Increased plasma levels of vasoactive intestinal polypeptide in pigs during endotoxinaemia.

Vasoactive intestinal polypeptide (VIP) is a highly potent vasodilatator. Cardiovascular changes and plasma VIP levels were studied during endotoxinaemia (Escherichia coli endotoxin 1 mg/kg) in a carefully monitored porcine model. Endotoxin infusion resulted in a profound but reversible shock and a substantial rise in plasma VIP levels. Increased levels of VIP could be demonstrated already after 30 min of endotoxin infusion and increased further during the infusion. Animals followed for a period of 60 h demonstrated slowly declining levels of VIP after endotoxin infusion but significantly elevated levels were usually found 24 h after infusion. Control animals did not show any changes in VIP during a similar procedure. Release of gastrointestinal peptides may be of importance during septic shock.