Abstract
The coronary circulation can be roughly divided into two compartments, the conducting arteries and the microcirculation. While epicardial vessels provide conduction pathways which exhibit very low resistance even during high flow, the microcirculation exhibits resistance within small arteries and arterioles and provides a large area for the exchange of oxygen, carbon dioxide, and nutrients within the capillaries. The regulation of flow is achieved at the site of the microcirculation by active dilatory mechanisms. A prerequisite for substantial dilation is the presence of constriction (vascular tone) which is generated by the vessel’s response to transmural pressure differences and concomitant generation of wall tension (myogenic tone). The active dilatory mechanisms consist of metabolic pathways generated by the action of the cardiomyocytes as well as dilator signals originating in endothelial cells. They produce in response to different stimuli endothelium-dependent dilation which is crucial for the enhancement of coronary flow during enhanced oxygen demands. These mechanisms include generation of nitric oxide as well as initiating smooth muscle hyperpolarisation through pathways that are not fully resolved yet but include release of potassium ions, hydrogen peroxide, and epoxyeicosatrienoic acids (EDHF). In addition, direct current transfer from endothelial cells to smooth muscle through myoendothelial gap junctions contributes.
Original language | English |
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Title of host publication | Microcirculation : From Bench to Bedside |
Number of pages | 18 |
Publisher | Springer International Publishing |
Publication date | 04.11.2019 |
Pages | 3-20 |
ISBN (Print) | 9783030281984 |
ISBN (Electronic) | 9783030281991 |
DOIs | |
Publication status | Published - 04.11.2019 |
Research Areas and Centers
- Academic Focus: Center for Brain, Behavior and Metabolism (CBBM)