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Isolation of Microvascular Endothelial Tubes from Mouse Resistance Arteries
Published on: November 26, 2013
Factors, fiction and endothelium-derived hyperpolarizing factor
1Division of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia. Shaun.Sandow@anu.edu.au
Clinical and Experimental Pharmacology & Physiology
|October 14, 2004
Summary
Endothelium-derived hyperpolarizing factor (EDHF) mediates vascular tone through direct cell coupling via myoendothelial gap junctions (MEGJ). Heterogeneity in EDHF action is explained by MEGJ
Area of Science:
- Cardiovascular Physiology
- Endothelial Function
- Vascular Biology
Background:
- Vascular tone is regulated by neural, endothelial, and physical stimuli, with endothelium-derived nitric oxide (NO) and prostaglandins being key vasodilators.
- An additional endothelium-dependent vasodilation, endothelium-derived hyperpolarizing factor (EDHF), remains after NO and prostaglandin inhibition, involving diffusible factors or direct cell contact.
- The precise nature and mechanism of EDHF action are debated, with evidence suggesting a role for myoendothelial gap junctions (MEGJ) in mediating endothelium-derived hyperpolarization (EDH).
Purpose of the Study:
- To review proposed EDHF factors and highlight laboratory studies demonstrating the role of MEGJ in EDH conduction.
- To explain the heterogeneity observed in EDHF/EDH(F) action and incorporate reported diffusible mechanisms.
- To examine how experimental design and technique contribute to the heterogeneity in EDHF/EDH(F) research.
Main Methods:
- Review of existing literature on EDHF mechanisms and heterogeneity.
- Analysis of correlative structural and functional studies focusing on MEGJ.
- Examination of experimental designs and techniques used in EDHF research.
Main Results:
- Evidence strongly supports contact-mediated mechanisms for EDHF activity, involving electrical current transfer (EDH) through MEGJ between endothelial and smooth muscle cells.
- Heterogeneity in EDHF/EDH(F) action is observed across different vascular beds, species, and physiological/pathological conditions.
- MEGJ play an integral role in conducting EDH, contributing to the observed heterogeneity in EDHF/EDH(F) function.
Conclusions:
- Myoendothelial gap junctions (MEGJ) are crucial for mediating endothelium-derived hyperpolarization (EDH), explaining a significant portion of EDHF heterogeneity.
- The variability in EDHF/EDH(F) action is influenced by factors including MEGJ function, diffusible factors, and species-specific differences.
- Critical evaluation of experimental design and methodology is essential for resolving discrepancies and advancing understanding of EDHF mechanisms.
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