CUTANEOUS LOCALIZATION OF ENDOTHELIN-1 IN PATIENTS WITH SYSTEMIC-SCLEROSIS - IMMUNOELECTRON MICROSCOPIC STUDY

Background Endothelin-1 (ET-1) has some relation to the pathogenesis o f systemic sclerosis (SSc) and Raynaud's phenomenon. This study was pe rformed to determine the localization of ET-1 in patients with SSc. Me thods The localization of ET-1 on the specimen by skin biopsies from n ine patients with SSc, was observed with immunoelectron microscopic te chniques. Results High-density deposits existed on the ribosomes and o n the rough endoplasmic reticulum in the endothelial cells of microves sels of the upper dermis. The same findings were also seen in the fibr oblasts of the dermis, but not found in the skin of normal controls. T he level of deposits in the endothelial cells and dermal fibroblasts s eemed 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 contro ls. It is suspected that ET-1 is one of the pathogenetic factors of SS c.