Abstract
Endothelin-1 stimulates collagen synthesis and is increased in hypertension, but its effect on collagen degradation remains unknown. The current study tested the hypothesis that elevated endothelin-1 levels are associated with decreased collagenase activity, markers of collagen degradation, and arterial compliance in hypertensive patients. Normotensive (n = 10) and hypertensive (n = 13) patients who were not on any antihypertensive medication were recruited, and small and large artery elasticity index, systemic vascular resistance, pulse pressure, and blood pressure were determined using blood pressure waveform analysis. Large artery elasticity index and collagen degradation products were decreased whereas endothelin-1, systemic vascular resistance, and pulse pressure were elevated in hypertensive patients. Plasma endothelin-1 was negatively correlated with a cross-linked C-terminal telopeptide of collagen type I, a collagen degradation marker (r = -0.43; p = 0.04), collagenase matrix metalloproteinase-1 (r = -0.48; p = 0.02), and large artery elasticity (r = -0.45; p = 0.03) and positively correlated with pulse pressure (r = 0.68; p = 0.0005). These results suggest that endothelin-1 contributes to decreased arterial compliance in hypertension via inhibition of collagen degradation.