ENDOTHELIN IN HEPATIC FIBROSIS-
of this transition include loss of vitamin A, acquisition of stress bundles, development of prominent rough en-
FRIEND OR FOE?
doplasmic reticulum, increased secretion of extracellu-Mallat A, Fouassier L, Preaux AM, Serradeil-Le Gal lar matrix proteins, and, importantly for the purposes C, Raufaste D, Rosenbaum J, Dhumeaux D, et al. of this discussion, enhanced cellular proliferation. A Growth inhibitory properties of endothelin-1 in human further important characteristic of activation is the achepatic myofibroblastic Ito cells. An endothelin B requisition by stellate cells of the smooth-muscle marker, ceptor-mediated pathway. J Clin Invest 1995;96:42smooth-muscle a actin. Such data have helped estab-49. lish that during liver injury, stellate cells transform into myofibroblasts, a mesenchymal cell type charac-ABSTRACT teristic of many healing wounds. Quantitative studies comparing messenger RNA (mRNA) for types I, III, Ito cells play a pivotal role in the development of liver fibrosis associated with chronic liver diseases. During and IV collagen after liver injury in stellate cells have this process, Ito cells acquire myofibroblastic features, demonstrated a greater than 50-fold increase in stelproliferate, and synthesize fibrosis components. Considlate cells, indicating that this cell type is largely reering the reported mitogenic properties of endothelin 1 sponsible for the fibrosing response to injury.
(ET-1), we investigated its effects on the proliferation of