The fate of radioiodinated endothelin-1 and endothelin-3 in the rat.

摘要: Endothelin-1 (ET-1) has been isolated from cultured endothelial cells and might have a role in cardiovascular regulation. To study the fate of labeled ET-1, we prepared (/sup 125/I)-labeled ET-1 (formerly porcine human ET) ET-3 rat ET). Approximately 0.2 microCi (0.2 pmol) was injected into left ventricle anesthetized rats blood samples analyzed for radioactivity up to 40 min. The animals were then killed distribution determined various organs. Both rapidly removed circulation, with more than 60% removal occurring first minute. Removal somewhat faster that ET-3. highest uptake seen lung, kidney, liver. When infused perfused lung guinea pig, 64 +/- 1.9% label retained. Subcellular fractionation homogenate following infusion showed 93% associated membranes intracellular organelles, suggesting internalization bound ET-1. Together, results indicate high density binding sites liver, kidney these organs may be important removing circulatingmore » ET-1.« less