Endothelial Anatomy of the Human Heart:
Immunohistochemical Evaluation of
Endothelial Differentiation

Introduction

The endothelial lining is a confluent monolayer of thin and rhomboid shaped cells that covers the inner surface of all blood vessels. Until the early sixties, endothelial cells were thought to be “not much more than a sheet of nucleated cellophane” [1]. However, the essential role of endothelial cells in all aspects of cardiovascular physiology and homeostasis [2] [3] [4] and the pathogenesis of most cardiovascular diseases no longer remain controversial. It is well-known that phenomena such as hemostasis, inflammation, and complex immune reactions require close interactions between immunocompetent and endothelial cells [5].

Although much evidence has been achieved regarding the molecular functioning of transcription factors and regulatory proteins, many questions on 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 various vascular sites of the healthy human heart. Using this map, we have examined whether expression patterns can be distinguished through their molecular function at their site of origin. Furthermore, immunohistochemical findings were associated with the clinical situation.

In contrast to numerous other studies using isolated cell culture models of non-cardiac endothelial cells [6] or animal models [7], our study allows for a direct and differential investigation of endothelial cells at all vascular sites of the human heart and under in vivo conditions.

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