<prompt> Endothelium derived relaxing factor EDRF induced vasodilatation is mediated by:Increased intracellular cGMPDecreased intracellular cGMPIncreased extracellular cyclic AMPDecreased intracellular cyclic AMP  <response>: Endothelial cells produce endothelium derived relaxing factor EDRF, a substance that is now known to be nitric oxide NO.NO and ANP hormone act via increasing intracellular cGMP. 