The origin and fall of plasma motilin during Escherichia coli endotoxin shock in pigs.

Plasma motilin decreased significantly during a 120 min intravenous Escherichia coli endotoxin infusion which induced deep shock in six anaesthetized pigs. Plasma motilin was significantly higher in the portal vein and significantly lower in the internal jugular vein than in the aorta and the superior caval vein. Following gastrointestinal resection with blood sampling from the portal vein, the aorta and the superior caval vein in another six pigs, motilin almost disappeared in non-portal plasma, while it decreased significantly in portal plasma in which it also fell further during E. coli endotoxin infusion. The results support the opinion that the gastrointestinal tract is the main source of plasma motilin.