ENDOTHELIUM‐DERIVED RELAXING FACTOR RELEASED FROM CULTURED CELLS: DIFFERENTIATION FROM NITRIC OXIDE

Abstract

1. Endothelium‐derived relaxing factor (EDRF) is an extremely labile mediator thought to be identical to nitric oxide (NO). 2. A cascade superfusion technique was used to bioassay EDRF released from bovine aortic endothelial cells grown to confluence on microcarrier beads. 3. Bradykinin (1–100 nmol/1), infused through a 1 cm column of endothelial cells on microcarriers, released an EDRF‐like substance that caused relaxations of de‐endothelialized strips of rabbit aorta (precontracted with phenylephrine). These relaxations diminished on successive tissues in the cascade, when compared with those produced by glyceryl trinitrate as a stable standard. 4. Haemoglobin (1 μmol/1), infused directly ..