[Endothelial function and spasm of the coronary artery]

Area of Science:

• Cardiovascular Biology
• Vascular Physiology
• Atherosclerosis Research

Background:

• Atherosclerosis is a significant risk factor for cardiovascular diseases.
• Coronary artery function is crucial for maintaining adequate blood flow to the heart.
• Endothelial dysfunction is implicated in the pathogenesis of coronary artery disease.

Purpose of the Study:

• To investigate the functional changes in human coronary arteries affected by atherosclerotic lesions.
• To assess the role of the endothelium in mediating relaxation responses in diseased coronary arteries.
• To explore the potential link between endothelial dysfunction and coronary artery spasm.

Main Methods:

• Isolated human coronary artery segments with and without atherosclerotic lesions were used.
• Vascular tone was measured in response to vasoactive agents like serotonin and prostaglandin F2 alpha.
• Endothelium-dependent relaxation was evaluated using bradykinin, calcium ionophore A-23187, and substance P.

Main Results:

• Serotonin and prostaglandin F2 alpha increased the tone of coronary artery segments with atherosclerotic lesions.
• Endothelium-dependent relaxation was impaired in segments with both visible and invisible atherosclerotic damage.
• Coronary artery segments without sclerotic damage exhibited normal endothelium-dependent relaxation.

Conclusions:

• Functional disturbances in the coronary artery endothelium, particularly in endothelial relaxation factor production, are evident in atherosclerosis.
• Impaired endothelial function contributes to increased smooth muscle contraction.
• This dysfunction is a potential mechanism underlying coronary artery spasm, angina pectoris, and myocardial infarction.