Figure 1.

Effects of endothelin include stimulating myofibroblast formation, leading to a concomitant increase in collagen production and fibrosis. Binding of endothelin (ET)-1 to ET-1 receptor subtype A (ET_A) and ET_B has different effects in different cell types. The binding of ET-1 to smooth muscle cell ET_A and ET_B receptors leads to vasoconstriction and mitogenesis, and activation of ET_B receptors on endothelial cells promotes the release of nitric oxide and prostacyclin, and plays a minor role in endothelial dependent vasodilatation. In fibroblasts ET-1 results in the increased production of collagen and leads to fibrosis. Reproduced with permission from Galiè et al. Cardiovascular Research ^© Elsevier 2004 [4].