Evans Blue Dye and the Development of “Myogenic Tone” in Perfused Resistance Vessels 1

Summary

Injection of Evans blue into the perfusate of isolated resistance vessels results in a large, persistent increase in perfusion pressure in skeletal muscle arteries and only a minor increase in mesenteric arteries. The induction of tone is associated with an increase in response to bolus injections of calcium chloride. It is suggested that the dye exerts its effect by increasing cell membrane permeability to extracellular calcium.