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[Clinical significance of endothelial dysfunction: studies of human coronary circulation in vivo]
1Abteilung Kardiologie, Università degli Studi, Napoli, Italien.
Insights
Endothelial cells modulate blood vessel tone. In coronary heart disease, dysfunction leads to vasoconstriction, potentially causing angina and heart attack.
Area of Science:
- Cardiovascular Physiology
- Endothelial Cell Function
- Vascular Biology
Context:
- Endothelial cells play a crucial role in regulating vascular tone.
- The discovery of endothelial modulation of smooth muscle cells dates back to 1980.
- Substances like thrombin, serotonin, and histamine also affect endothelial cells.
Purpose:
- To investigate the role of endothelial cells in coronary circulation.
- To understand the impact of endothelial dysfunction in coronary heart disease.
- To explore the mechanisms behind altered vasomotor responses in arteriosclerotic coronary segments.
Summary:
- Endothelial cells modulate the tone of vascular smooth muscle cells.
- In healthy coronary arteries, substances like acetylcholine induce vasodilation.
- Arteriosclerotic coronary segments exhibit vasoconstriction in response to acetylcholine and serotonin, indicating endothelial dysfunction.
Impact:
- Endothelial dysfunction is implicated in unstable angina pectoris.
- Disturbed vasomotor regulation may contribute to myocardial infarction development.
- Understanding these mechanisms is vital for diagnosing and treating coronary heart disease.
Abstract:
One of the most fascinating findings concerning our knowledge on the physiology of the cardiovascular system, especially the coronary circulation, concerns the modulating capacity of the endothelial cells on the tone of smooth muscle cells. This phenomenon was described for the first time in the aorta of a rabbit in 1980 by Furchgott and Zawadzki using acetylcholine as stimulator. Later, however, it became clear that other substances that are likewise of interest in the context of coronary heart disease, like thrombin, serotonin and histamine, have the same effect on endothelial cells. These effects can also be demonstrated in the human coronary circulation during cardiac catheterization. While normal coronary segments show a vasodilatation (corresponding to the endothelial relaxation in vitro) in arteriosclerotic coronary segments, vasoconstriction is induced by acetylcholine and serotonin. A disturbance of this vasomotor process mediated by endothelial vasomotor processes may be of particular importance in instable angina pectoris and for the development of myocardial infarction.