Endothelin-1 and endotoxemia.

Sepsis leads to changes in blood volume and distribution. In the experiments reported here we monitored circulatory changes during endotoxemia and their relation to portal and systemic levels of endothelin-1 (ET-1). Piglets were monitored cardiovascularly under ketamine anesthesia for 6 h after an endotoxin infusion (saline controls). ET-1 levels in plasma were analyzed by RIA. In both portal and systemic blood a twofold increase in ET-1 levels was found after 1 h. This level remained significantly elevated for a further 3 h. This increase was concurrent with a drop in cardiac output, systemic vascular resistance, and blood pressure. In the portal circulation there was increased portal pressure and vascular resistance. There was no significant difference between the systemic and portal levels of ET-1.