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The endothelial glycocalyx protects against myocardial edema
Bernard M van den Berg1, Hans Vink, Jos A E Spaan
1Department of Medical Physics, Academic Medical Center, University of Amsterdam, PO Box 22700, 1100 DE Amsterdam, The Netherlands.
Insights
A protective carbohydrate layer on heart capillaries prevents fluid leakage and tissue swelling. Degradation of this layer causes immediate myocardial tissue edema, impacting cardiac function.
Area of Science:
- Cardiovascular Biology
- Endothelial Cell Biology
- Microvascular Physiology
Background:
- Myocardial tissue edema, caused by microvascular fluid loss, impairs cardiac function following events like ischemia, surgery, hypertension, and sepsis.
- Carbohydrate structures on the endothelium's surface are implicated in preventing tissue edema.
Purpose of the Study:
- To investigate the role of endothelial carbohydrate structures in preventing myocardial tissue edema.
- To visualize and characterize the carbohydrate layer on rat myocardial capillaries.
Main Methods:
- Preservation of endothelial carbohydrate structures for electron microscopy.
- Visualization of the rat myocardial capillary endothelial surface using electron microscopy.
Main Results:
- The rat myocardial capillary endothelial surface possesses a carbohydrate layer 0.2–0.5 microm thick.
- Degradation of this carbohydrate layer led to immediate and significant myocardial tissue edema.
Conclusions:
- The endothelial carbohydrate layer is crucial for maintaining vascular barrier integrity and preventing myocardial edema.
- Disruption of this layer has direct and rapid pathological consequences on myocardial tissue.
Abstract:
Myocardial tissue edema attributable to increased microvascular fluid loss contributes to cardiac dysfunction after myocardial ischemia, cardiopulmonary bypass, hypertension, and sepsis. Recent studies suggest that carbohydrate structures on the luminal surface of microvascular endothelium are essential to prevent tissue edema. We carefully preserved these structures for visualization with electron microscopy, revealing that the rat myocardial capillary endothelial surface is coated with a 0.2- to 0.5-microm-thick carbohydrate layer and that its degradation instantly results in notable myocardial tissue edema.