Hepatic lipocytes: a major target for endothelin-1.

Lipocytes are the predominant target for ET-1 within the normal and fibrotic liver. ET-1-induced contraction of lipocytes becomes prominent in liver injury. In this setting, ET-1 may have an autocrine role in regulating sinusoidal flow, in association with eicosanoids and other endothelium derived factors such as nitric oxide (NO). In more advanced fibrosis, ET-1 may participate in contraction of collagen bands causing distortion of the lobular structure. A direct role of ET-1 in the activation of lipocytes is still hypothetical but could represent additional effects of ET-1 in various stages of liver fibrogenesis via paracrine and/or autocrine routes.