Role of endothelin-1 in the failure of cerebral circulation after complete global cerebral ischemia.

Abstract

The role of endothelin-1 (ET-1) in the failure of cerebral circulation after cardiac arrest is unknown. We evaluated the effect of complete global cerebral ischemia that was induced on the plasma ET-1 concentration in 5 dogs, by occluding the ascending aorta and caval veins for 15 min. A fiberoptic catheter was inserted into the sagittal sinus for the continuous monitoring of venous oxygen saturation. Blood samples were collected before and at 0.5, 1, 2, 4, and 6 h after the ischemic insult. The ET-1 concentration in the sagittal sinus and abdominal aorta was assayed. Complete global cerebral ischemia resulted in a significant 3-fold increase in the sagittal sinus concentration of ET-1 (P < 0.01) that was associated with a significant decrease in the sagittal sinus venous oxygen saturation (P < 0.01); the arterial ET-1 concentration remained unchanged. The difference between arterial and venous ET-1 concentrations during the hypoperfusion phase subsequent to the ischemic insult may result from an increased secretion of ET-1 by the cerebrovasculature and a decrease in the clearance of ET-1 in the cerebral circulation. The result suggests that ET-1 may contribute to the failure of cerebral circulation after cardiac arrest.