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Updated: Aug 9, 2026
11:02
Exploring Arterial Smooth Muscle Kv7 Potassium Channel Function using Patch Clamp Electrophysiology and Pressure Myography
Published on: September 14, 2012
Capillaries demonstrate changes in membrane potential in response to pharmacological stimuli
E D McGahren1, J M Beach, B R Duling
1Department of Surgery, University of Virginia Health Sciences Center, Charlottesville 22906-0011, USA.
The American Journal of Physiology
|February 12, 1998
Summary
Capillary endothelial cells can change their membrane potential in response to stimuli. This finding suggests capillaries may detect tissue changes and signal upstream vessels.
Area of Science:
- Physiology
- Vascular Biology
- Cellular Electrophysiology
Background:
- Capillaries are proposed to detect tissue metabolites and signal upstream resistance vessels.
- The mechanism may involve capillary endothelial cell membrane potential changes conducted to arterioles.
Purpose of the Study:
- To test the in vivo capacity of capillary endothelial cells to respond to pharmacological stimuli.
- To investigate if capillary membrane potential changes can be induced and measured.
Main Methods:
- Utilized a hamster cheek pouch preparation with voltage-sensitive dye (di-8-ANEPPS) in capillary endothelial cells.
- Measured fluorescence changes to estimate membrane potential shifts upon application of KCl, acetylcholine (ACh), and phenylephrine (PE).
Main Results:
- Potassium chloride (KCl) induced depolarization, while vehicle application did not.
- Acetylcholine (ACh) caused hyperpolarization, and phenylephrine (PE) caused depolarization.
- These responses were blocked by specific receptor antagonists (atropine for ACh, prazosin for PE).
Conclusions:
- Capillary endothelial cell membrane potential is responsive to pharmacological stimuli.
- This supports the hypothesis that capillaries can sense surrounding tissue milieu changes via membrane potential alterations.
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