| Research Abstract |
1) Clinical study
Endothelin-1 (ET-1) release during operation correlated (r=0.678) with bleeding volume during operation in patients with abdominal aortic aneurysm. In two patients with rapture of abdominal aortic aneurysm, elevated plasma ET-1 levels gradually decreased in survivor, whereas elevated ET-1 levels remained high in non-survivor. These findings suggest that plasma ET-1 levels reflect the degree of surgical stress and vascular injury.
2) Study of canine endotoxic shock model
LPS (250 ng/kg/min for 2 hr) induced hypotension, metabolic acidosis, hypoxemia, and renal dysfunction in anesthetized dogs. Plasma ET-1 levels increased and positively correlated with MAP, MPAP, PCWP, and CV'P in dogs with endotoxic shock. Pretreatment of nonselective ETィイD2AィエD2/ETィイD2BィエD2 receptor antagonist, TAK-044 (5 mg/kg), prevented LPS-induced metabolic acidosis, hypoxemia, and renal dysfunction. Therefore, TAK-044 is a useful agent to prevent acute renal failure during endotoxic shock. In addition, selective inducible NO synthase inhibitor, L-canavanine (10 mg/kg/hr for 5 hr), further increased plasma ET-1 levels, which were associated with decrease in DOィイD22ィエD2I and lactic acidosis. These findings suggest that ET-1 plays a compensatory role against vasodilation during endotoxic shock , but excessive ET-1 may decrease organ blood flow and induce organ dysfunction.
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