ELEVATED PLASMA ENDOTHELIN LEVELS IN SYSTEMIC-SCLEROSIS

Endothelin is a novel potent vasoconstrictor peptide produced mainly b y endothelial cells. Thrombomodulin is a high-affinity thrombin recept or on vascular endothelial cells that plays an important role as a nat ural anticoagulant. In this study, we measured plasma levels of endoth elin and thrombomodulin in patients with systemic sclerosis or Raynaud 's disease. Plasma levels of endothelin and the ratio of thrombomoduli n to creatinine were significantly increased in patients with systemic sclerosis compared with normal controls, and there was a positive cor relation between these two indicators (r = 0.615, P = 0.004). Moreover , plasma levels of endothelin were significantly higher in patients wi th diffuse systemic sclerosis than in patients with limited systemic s clerosis. In contrast, plasma levels of endothelin in patients with Ra ynaud's disease were not significantly increased. These results sugges t that increased plasma levels of endothelin and thrombomodulin may re flect microvascular damage in systemic sclerosis.