[125I]endothelin-1 binding sites: autoradiographic studies in the brain and periphery of various species including humans.

Quantitative autoradiography with [125I]-endothelin-1 (ET-1) has been used to localize putative ET-1 recognition sites in the brain and peripheral organs of various species including humans. High densities of high-affinity [125I]ET-1 binding sites were observed in heart, lung, liver, kidney, blood vessels, and brain. A differential pattern of distribution of ET-1 recognition sites was observed in the periphery and in the brain, indicating that putative ET-1 receptors are not located only in blood vessels. The data are consistent with a role for ET-1 in vascular smooth muscle and nonvascular tissues, such as heart, lung, intestine, kidney, and brain.