THE HALF-LIFE OF ENDOTHELIUM-DERIVED RELAXING FACTOR RELEASED FROM BOVINE AORTIC ENDOTHELIAL-CELLS IN CULTURE

Abstract

1. The half-life of endothelium-derived relaxing factor (EDRF) in Krebs solution was determined by bioassay in vitro. 2. A column of bovine aortic endothelial cells grown on microcarrier beads in suspension culture was perfused with Krebs solution. EDRF was released from these cells by sequential treatment with increasing concentrations of bradykinin (0.01-100 nM). EDRF was detected by the relaxation of an endothelium-denuded ring segment of dog coronary artery. 3. Complete bradykinin concentration-relaxation curves were determined in the absence or presence of coils of tubing that increased the transit time (delay) between the cell column and the assay tissue. An estimate of the falls in co..