Endothelial anatomy of the human heart: immunohistochemical evaluation of endothelial differentiation.
OBJECTIVE
Endothelial cells play a significant role in cardiovascular physiology and the pathogenesis of numerous cardiovascular diseases. Essential phenomena such as hemostasis, inflammation and immunity require close interactions between immunocompetent and endothelial cells. However, many questions of endothelial heterogeneity regarding function and morphology at various vascular sites remain unanswered. In this study, we have created an immunohistochemical map of endothelial adhesion molecule expression at different vascular sites of the healthy human heart. The main focus was to analyze endothelial expression patterns and whether they are distinctive regarding their function at these vascular sites. We also tried to build up a relation between clinical and immunohistochemical findings.


METHODS
Tissue samples from eleven different vascular locations of healthy human hearts were analyzed using immunohistochemistry. Endothelial adhesion molecules of the selectin, immunoglobulin supergene, and integrin families, some complementary cellular adhesion molecules, and von Willebrand factor were analyzed.


RESULTS
Endothelial adhesion molecule expression was found to be characteristic for all vascular sites investigated. Thus, molecules involved in inflammatory reactions were predominantly expressed within the myocardial microvasculature, whereas molecules serving endothelial anchorage towards extracellular matrix components could be observed especially on endocardial and valvular surfaces. Apart from that, a parallel expression of immunologically relevant as well as integrin molecules was found to be characteristic for coronary arteries.


CONCLUSIONS
To our knowledge, this is the first report on site-specific expression characteristics for all vascular sites of the human heart. Thus, our data provide important novel information, which will ultimately help to bring some light into the field of cardiac physiology.
Wilhelmi
M
M
Division of Thoracic and Cardiovascular Surgery, Hanover Medical School, Hanover, Germany. Wilhelmi@thg.mh-hannover.de
Fischer
S
S
Leyh
R
R
Mertsching
H
H
Haverich
A
A
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002454:Cell Differentiation; D004730:Endothelium, Vascular / Q000166:cytology*; D006801:Humans; D007150:Immunohistochemistry; D016023:Integrins / Q000378:metabolism; D009206:Myocardium / Q000166:cytology*; D038981:Receptors, Collagen
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D016023:Integrins; D038981:Receptors, Collagen