The initial vasodilation and the later vasoconstriction of endothelin-1 are selective to specific vascular beds.

The regional hemodynamic effects of endothelin-1 (ET-1) were studied in Wistar-Kyoto rats. Endothelin-1 caused a transient increase in blood flow in the carotid and femoral arteries but a decrease in flow in the renal and mesenteric arteries. The resistance in the carotid and femoral beds decreased while it increased in the renal and mesenteric beds. Subsequently there was a variable increase in resistance in all vascular beds with a maximal increase in the renal bed. Thus, ET-1 initially causes a selective vasorelaxation in musculocutaneous beds but not in visceral beds; the cause of this selectivity is unknown.