Circulating and tissue endothelin immunoreactivity in advanced atherosclerosis.

Area of Science:

• Cardiovascular Research
• Vascular Biology
• Biomarker Discovery

Background:

• Atherosclerosis involves endothelial injury and smooth muscle cell proliferation.
• Growth factors released from the vessel wall may contribute to smooth muscle cell proliferation.
• Endothelin, an endothelium-derived peptide, possesses vasoconstrictor and mitogenic properties.

Purpose of the Study:

• To test the hypothesis that plasma endothelin concentrations are elevated in individuals with symptomatic atherosclerosis.
• To investigate the relationship between plasma endothelin levels and age in normal subjects and patients with atherosclerosis.

Main Methods:

• Plasma endothelin levels were measured in 100 normal subjects and 40 patients with various types of atherosclerosis.
• Immunohistochemical staining was performed on atherosclerotic vessel walls to detect endothelin.
• Statistical analysis was used to correlate endothelin levels with age and disease involvement.

Main Results:

• Normal subjects had a mean plasma endothelin of 1.4 +/- 0.2 pmol/L, with no age correlation.
• Patients with symptomatic atherosclerosis showed significantly higher mean plasma endothelin of 3.2 +/- 1.2 pmol/L (P < 0.001).
• A strong correlation was found between plasma endothelin and the number of affected arterial sites (r = 0.89, P < 0.001).
• Endothelin-1-like immunoreactivity was detected in both vascular smooth muscle and endothelial cells of atherosclerotic vessels.

Conclusions:

• Elevated plasma endothelin may serve as a marker for arterial vascular disease.
• The precise role of endothelin in the atherogenic process requires further investigation.
• Endothelin might be released from damaged endothelial cells during atherosclerosis.