LED Photobiomodulation Improves Radial Artery Vascular Function in Vitro

University of Sao Paulo30 enrolled

Overview

LED photobiomodulation therapy (PBMT) is widely recognized for its beneficial effects in several clinical conditions; however, its potential in modulating vascular function is not yet fully established. Objective: This study aimed to evaluate the application of PBMT by LED (light-emittion diode) using a combined red and near-infrared light spectrum, with a focus on improving the vascular function of the radial artery in vitro. Methodology: A total of 30 radial artery segments were studied and divided into three groups of 10 segments: the PBMT LED group combined with red and infrared light (R + IR), the red light (R) group, and the infrared light (IR) group. Prior to light irradiation at wavelengths of 650 nm and 940 nm, vascular function in these segments was pharmacologically inhibited using L-NAME. The drugs phenylephrine, acetylcholine, and sodium nitroprusside were used to determine if irradiation could restore the inhibited vascular functions. Superoxide anion levels, an important reactive oxygen specie (ROS), were measured using a chemiluminescence assay with lucigenin. The bioavailability of nitric oxide was evaluated using a Griess Reagent Kit assay, while nitric oxide production was assessed through the DAF fluorescence assay. The vascular inflammation was determined by the Intercellular Adhesion Molecule 1 (ICAM-1) expression.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Enrollment

Conditions

Vascular Dysfunction

Interventions

Light-emitting diode photobiomodulation therapyDEVICE

For the intervention, the isolated arteries were assigned to three experimental groups. The first group (red) was exposed to light at a wavelength of 650 nm for 83 seconds. The second group (infrared) received irradiation at 940 nm for 94 seconds. The third group (mixed) was irradiated with a combination of red (650 nm) and infrared (940 nm) light for 73 seconds.

Outcomes

Primary Outcomes

Diameter of Isolated Radial Artery Rings (2 mm)

Description of Primary Outcome Measure(s): The primary outcome of this study is the evaluation of vascular compliance during vasodilation of isolated radial artery rings (2 mm in diameter), with a specific focus on the effects of LED photobiomodulation on arterial function.

Time frame: 12 months

Secondary Outcomes

Evaluation of reactive oxygen species (ROS)

Superoxide anion (O₂--) generation, a key reactive oxygen species (ROS), will be measured in arterial tissue from the R + IR, R, and IR groups using a lucigenin-enhanced chemiluminescence assay. Lucigenin will serve as the electron acceptor, and nicotinamide adenine dinucleotide phosphate (NADPH) as the substrate. Results will be expressed as a percentage of concentration.