Cutaneous localization of endothelin-1 in patients with systemic sclerosis: Immunoelectron microscopic study

Background Endothelin-1 (ET-1) has some relation to the pathogenesis of systemic sclerosis (SSc) and Raynaud's phenomenon. This study was performed to determine the localization of ET-1 in patients with SSc. Methods The localization of ET-1 on the specimen by skin biopsies from nine patients with SSc, was observed with immunoelectron microscopic techniques. Results High-density deposits existed on the ribosomes and on the rough endoplasmic reticulum in the endothelial cells of microvessels of the upper dermis. The same findings were also seen in the fibroblasts of the dermis, but not found in the skin of normal controls. The level of deposits in the endothelial cells and dermal fibroblasts seemed to have a positive correlation with the serum levels of ET-1 of patients with SSc. Conclusions From these results, it can be seen that ET-1 is produced much more from the endothelial cells and fibroblasts of the dermis in the skin of SSc patients than from the normal controls. It is suspected that ET-1 is one of the pathogenetic factors of SSc.