Electromagnetic energy (670 nm) stimulates vasodilation through activation of the large conductance potassium channel (BKCa). PLoS One 2021;16(10):e0257896
Date
10/06/2021Pubmed ID
34610026Pubmed Central ID
PMC8491904DOI
10.1371/journal.pone.0257896Scopus ID
2-s2.0-85116591248 (requires institutional sign-in at Scopus site) 1 CitationAbstract
INTRODUCTION: Peripheral artery disease (PAD) is a highly morbid condition in which impaired blood flow to the limbs leads to pain and tissue loss. Previously we identified 670 nm electromagnetic energy (R/NIR) to increase nitric oxide levels in cells and tissue. NO elicits relaxation of smooth muscle (SMC) by stimulating potassium efflux and membrane hyperpolarization. The actions of energy on ion channel activity have yet to be explored. Here we hypothesized R/NIR stimulates vasodilation through activation of potassium channels in SMC.
METHODS: Femoral arteries or facial arteries from C57Bl/6 and Slo1-/- mice were isolated, pressurized to 60 mmHg, pre-constricted with U46619, and irradiated twice with energy R/NIR (10 mW/cm2 for 5 min) with a 10 min dark period between irradiations. Single-channel K+ currents were recorded at room temperature from cell-attached and excised inside-out membrane patches of freshly isolated mouse femoral arterial muscle cells using the patch-clamp technique.
RESULTS: R/NIR stimulated vasodilation requires functional activation of the large conductance potassium channels. There is a voltage dependent outward current in SMC with light stimulation, which is due to increases in the open state probability of channel opening. R/NIR modulation of channel opening is eliminated pharmacologically (paxilline) and genetically (BKca α subunit knockout). There is no direct action of light to modulate channel activity as excised patches did not increase the open state probability of channel opening.
CONCLUSION: R/NIR vasodilation requires indirect activation of the BKca channel.
Author List
Gebremendhin D, Lindemer B, Weihrauch D, Harder DR, Lohr NLAuthor
Dorothee Weihrauch DVM, PhD Research Scientist II in the Anesthesiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsElectric Stimulation
Electric Stimulation Therapy
Electromagnetic Radiation
Femoral Artery
Gene Knockout Techniques
Large-Conductance Calcium-Activated Potassium Channel alpha Subunits
Membrane Potentials
Mice
Mice, Knockout
Muscle, Smooth, Vascular
Myocytes, Smooth Muscle
Nitric Oxide
Patch-Clamp Techniques
Peripheral Arterial Disease
Signal Transduction
Vasodilation
