General Session

Abstract

Endothelin(ET) is a vasoconstrictor peptide derived from endothelial cells. We investigated the distribution of ET-like immunoreactivity in the cardiovascular system by use of immunohistochemical technique. The specimens were aorta, arteries, aortic valves, ventricles and pericardium of the heart obtained during operation, endomyocardial biopsy or autopsy. These were fixed in 10% buffered formalin and embedded in paraffin. The avidin-biotin peroxidase complex method was performed using the rabbit anti-human ET serum. ET-like immunoreactivity was observed in the cytoplasm of various endothelial cells, but not following immunoabsorption. The immunoreactivity was much higher in a variety of the endothelial cells under dynamically stressful conditions such as aortic and arterial aneurysm, Kawasaki disease, pericarditis, and hypertrophic cardiomyopathy. These results suggest that human cardiovascular endothelial. cells function as an endocrine and/or paracrine cells for ET secretion, especially in the pathological conditions.