Endothelial Effects and Angiogenesis

Vopr Kurortol Fizioter Lech Fiz Kult. 2014 May-Jun;(3):9-12.

[The influence of intravenous laser therapy on the endothelial function and the state of microcirculation in the patients presenting with rheumatoid arthritis].

[Article in Russian]
[No authors listed]



The objective of the present work was to study effects of low-level laser irradiation on the endothelial function and selected parameters of microcirculation in the patients presenting with rheumatoid arthritis.


This study included 132 patients at the age varying from 18 to 85 years presenting with rheumatoid arthritis. They were divided into 2 groups. The patients of the main group (n = 102) underwent daily intravenous laser blood irradiation during 10 days. The control group was comprised of 30 patients. Laser therapy was performed with the help of a laser therapeutic device Matrix – VLOK ("Matrix", Russia) using alternation of two radiating heads: KI-VLOK-63 (wavelength 0.63 pm, for 15 minutes) and KI-VLOK-365 (wavelength 0.365 microm, for 5 minutes) in the continuous emission regime. The parameters of interest were measured before and after the treatment. The overall duration of intravenous laser irradiation of blood was 10 days without a break for the weekend.


The data obtained suggest the improvement of the endothelial function and the microcirculation indices.


J Mol Cell Cardiol 2013 May 20

Far red/near infrared light treatment promotes femoral artery collateralization in the ischemic hindlimb.

Lohr NL, Ninomiya JT, Warltier DC, Weihrauch D

Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, USA; Department of Cardiovascular Center, Medical College of Wisconsin, USA; Clement J Zablocki VA Medical Center, USA. Electronic address: ntonn@mcw.edu.

Nitric oxide (NO) is a crucial mediator of hindlimb collateralization and angiogenesis. Within tissues there are nitrosyl-heme proteins which have the potential to generate NO under conditions of hypoxia or low pH. Low level irradiation of blood and muscle with light in the far red/near infrared spectrum (670nm, R/NIR) facilitates NO release. Therefore, we assessed the impact of red light exposure on the stimulation of femoral artery collateralization. Rabbits and mice underwent unilateral resection of the femoral artery and chronic R/NIR treatment. The direct NO scavenger carboxy-PTIO and the nitric oxide synthase (NOS) inhibitor L-NAME were also administered in the presence of R/NIR. DAF fluorescence assessed R/NIR changes in NO levels within endothelial cells. In vitro measures of R/NIR induced angiogenesis were assessed by endothelial cell proliferation and migration. R/NIR significantly increased collateral vessel number which could not be attenuated with L-NAME. R/NIR induced collateralization was abolished with c-PTIO. In vitro, NO production increased in endothelial cells with R/NIR exposure, and this finding was independent of NOS inhibition. Similarly R/NIR induced proliferation and tube formation in a NO dependent manner. Finally, nitrite supplementation accelerated R/NIR collateralization in wild type C57Bl/6 mice. In an eNOS deficient transgenic mouse model, R/NIR restores collateral development. In conclusion, R/NIR increases NO levels independent of NOS activity, and leads to the observed enhancement of hindlimb collateralization.

Klin Med (Mosk). 2008;86(6):44-7.

[Laser Doppler fluometry in assessment of endothelium state in patients with coronary heart disease and its correction by intravenous laser irradiation of blood]

[Article in Russian]

Burduli NM, Gazdanova AA.

Influence of laser therapy on vascular endothelium function in patients with stable angina pectoris, detected by the method of laser Doppler fluorimetry, was studied. 77patients with stable angina pectoris were divided into 2 groups. In control group only medicamentous therapy was used, in main group a course of intravenous blood laser irradiation was carried out additionally. The increase of initially decreased mean index of microcirculation and index of microcirculation after acetylcholine iontophoresis was noticed. Tendency to increase of endothelial oscillations and capillary blood flow under influence of intravenous blood laser irradiation was noticed too. Laser therapy can be considered an effective method of increase of endothelial functional activity in patients with stable angina pectoris.

Lasers Surg Med. 2008 Jan;40(1):46-54

Low-energy laser irradiation increases endothelial cell proliferation, migration, and eNOS gene expression possibly via PI3K signal pathway.

Chen CH, Hung HS, Hsu SH.

Institute of Biomedical Science, National Chung Hsing University, Taichung, Taiwan, Republic of China.

BACKGROUND AND OBJECTIVES: The purpose of this study, therefore, was to determine the mechanisms by which low-energy laser irradiation (LELI) may exert some of its angiogenic effects via the PI3 kinase/eNOS signaling pathway and induce endothelial cell migration and neovascularization, an important and necessary part of wound healing. STUDY DESIGN/MATERIALS AND METHODS: The possible molecular mechanism of helium-neon (He-Ne) laser irradiation on endothelial cells was proposed. He-Ne laser at 632.5 nm was used to stimulate human umbilical vein endothelial cell (HUVEC), and its effect on cell proliferation, nitric oxide secretion, and cell migration was determined. RESULTS: Irradiation enhanced endothelial nitric oxidase synthase (eNOS) protein expression, and irradiation of less than 0.26 J/cm(2) enhanced eNOS gene expression in HUVEC. The cell migration ability was promoted for HUVEC irradiated with 0.26 J/cm(2). This agreed with the vinculin protein expression induced by irradiation. In addition, the angiogenesis was promoted. The induced eNOS expression was inhibited by LY294002, indicating that the effect of laser on EC could be attributed to the up-regulation of eNOS expression through PI3K pathway at the cellular and molecular levels as a result of the He-Ne laser. CONCLUSIONS: The study has shown that LELI increased endothelial cell proliferation, migration, NO secretion, and identified that activation of PI3K/Akt pathway was a critical step for the elevated for eNOS expression upon LELI.

Curr Eye Res. 2007 Jul-Aug;32(7-8):625-38.

Effect of low fluence diode laser irradiation on the hydraulic conductivity of perfused trabecular meshwork endothelial monolayers.

Roberts CJ, Rivera BK, Grzybowski DM, Mahmoud AM, Weber PA.

Department of Ophthalmology, The Ohio State University, Columbus 43210, USA. roberts.8@osu.edu

OBJECTIVE: To determine the effect of low-fluence diode laser irradiation upon the fluid perfusion characteristics of cultured human trabecular meshwork cell monolayers when placed in a specially designed testing apparatus and subjected to fluid flow driven by a hydrostatic pressure gradient. METHODS: Two experimental series were conducted. In the first series, six low-fluence diode laser irradiation experiments were conducted using cultured human trabecular meshwork cell monolayers grown on filter supports. Upon reaching a steady state perfusion condition at approximately 5.0 mmHg, monolayers were irradiated at fluencies ranging from 0.2619 to 0.8571 J/cm2 using a diode laser (lambda=810 nm). Perfusion and data collection continued for 45 minutes post-irradiation, after which the monolayers were tested to determine post-experimental viability. Hydraulic conductivity values were analyzed for post-irradiation response in 2.5-minute intervals, grouped by viability. In the second series, a total of six irradiated experiments and six simultaneous nonirradiated control experiments were conducted. Fluence values of 0.3571 J/cm2 (n=3) and 0.4286 J/cm2 (n=3) were used. Hydraulic conductivity values were analyzed for post-irradiation response in 2.5-minute intervals, grouped by irradiated vs. nonirradiated control groups. RESULTS: In the first series, analysis showed that the viable monolayers exhibited a statistically significant increase in hydraulic conductivity (p<0.001) from 10 minutes post-irradiation onward. The non-viable monolayers exhibited a statistically significant decrease in hydraulic conductivity. In the second series, irradiated groups showed a significant difference (p<0.001) from nonirradiated controls from 10 minutes post-irradiation onward. CONCLUSION: Low-fluence diode laser irradiation increases hydraulic conductivity in viable perfused TM cell monolayers when compared to baseline values or simultaneous nonirradiated controls while decreasing hydraulic conductivity in nonviable monolayers.

Lasers Med Sci. 2007 Mar;22(1):30-6. Epub 2006 Nov 21.


Irradiation at 634 nm releases nitric oxide from human monocytes.


Lindgård A, Hultén LM, Svensson L, Soussi B.

Wallenberg Laboratory, Sahlgrenska University Hospital, Göteborg University, Gothenburg, 413 45, Sweden.

Previous studies have shown that irradiation at 634 nm decreases the release of extracellular reactive oxygen species (ROS) without affecting viability in human monocytes. Here, we examined the effect of irradiation at 634 nm on the release of nitric oxide (NO), activation of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS), and release of intracellular ROS. Chemiluminescence assays were used to measure NO release, intracellular ROS, and adenosine triphosphate levels (to assess cell viability). Levels of iNOS and eNOS mRNA were analyzed using PCR. Irradiation resulted in elevated levels of NO but had no effect on iNOS or eNOS. Irradiation also caused a decrease in levels of intracellular ROS and had no effect on cell viability. Our studies indicate that irradiation at 634 nm releases NO, possibly from a preformed store, and reduces the production of intracellular ROS without affecting cell viability. Irradiation at 634 nm may have a wide range of clinical applications, including a reduction in oxidative stress-mediated injury in the vasculature.

Lasers Surg Med. 2006 Aug;38(7):682-8.

Modulations of VEGF and iNOS in the rat heart by low level laser therapy are associated with cardioprotection and enhanced angiogenesis.

Tuby H, Maltz L, Oron U.

Department of Zoology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel.


BACKGROUND AND OBJECTIVES: It has been shown previously that low-level laser therapy (LLLT) significantly reduces infarct size following induction of myocardial infarction in rats and dogs. The aim of the present study was to investigate the effect of LLLT on the expression of vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS). STUDY DESIGN AND

MATERIAL AND METHODS: Myocardial infarction was induced by occlusion of the left descending artery in 87 rats. LLLT was applied to intact and post-infarction. VEGF, iNOS, and angiogenesis were determined.

RESULTS: Both the laser-irradiated rat hearts post-infarction and intact hearts demonstrated a significant increase in VEGF and iNOS expression compared to non-laser-irradiated hearts. LLLT also caused a significant elevation in angiogenesis.

CONCLUSIONS: It is concluded that VEGF and iNOS expression in the infarcted rat heart is markedly upregulated by LLLT and is associated with enhanced angiogenesis and cardioprotection.

Lasers Surg Med. 2001;28(4):355-64.

Low-power helium: neon laser irradiation enhances production of vascular endothelial growth factor and promotes growth of endothelial cells in vitro.

Kipshidze N, Nikolaychik V, Keelan MH, Shankar LR, Khanna A, Kornowski R, Leon M, Moses J.

Lenox Hill Heart and Vascular Institute and Cardiovascular Research Foundation, New York, New York 10021, USA.

BACKGROUND AND OBJECTIVE: Numerous reports suggest that low-power laser irradiation (LPLI) is capable of affecting cellular processes in the absence of significant thermal effect. The objective of the present study was to determine the effect of LPLI on secretion of vascular endothelial growth factor (VEGF) and proliferation of human endothelial cells (EC) in vitro. STUDY DESIGN/MATERIALS AND METHODS: Cell cultures were irradiated with single different doses of LPLI (Laser irradiance from 0.10 to 6.3 J/cm(2)) by using a He:Ne continuous wave laser (632 nm). VEGF secretion by smooth muscle cells (SMC) and fibroblasts was quantified by sandwich enzyme immunoassay technique. The endothelial cell proliferation was measured by Alamar Blue assay. VEGF and transforming growth factor beta (TGF-beta) expression by cardiomyocytes was studied by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: We observed that (1) LPLI of vascular and cardiac cells results in a statistically significant increase of VEGF secretion in culture (1.6-fold for SMC and fibroblasts and 7-fold for cardiomyocytes) and is dose dependent (maximal effect was observed with LPLI irradiance of 0.5 J/cm(2) for SMC, 2.1 J/cm(2) for fibroblasts and 1.05 J/cm(2) for cardiomyocytes). (2) Significant stimulation of endothelial cell growth was obtained with LPLI-treated conditioned medium of SMC (maximal increase was observed with LPLI conditioned medium with irradiance of 1.05 J/cm(2) for SMC and 2.1 J/cm(2) for fibroblasts. CONCLUSIONS: Our studies demonstrate that low-power laser irradiation increases production of VEGF by SMC, fibroblasts, and cardiac myocytes and stimulates EC growth in culture. These data may have significant importance leading to the establishment of new methods for endoluminal postangioplasty vascular repair and myocardial photoangiogenesis.

Cardiovasc Radiat Med. 1999 Jul-Sep;1(3):265-9.

Augmentation of the expression of proangionic genes in cardiomyocytes with low dose laser irradiation in vitro.

Khanna A, Shankar LR, Keelan MH, Kornowski R, Leon M, Moses J, Kipshidze N.

Medical College of Wisconsin, Milwaukee, USA.

BACKGROUND AND OBJECTIVE: Several reports suggest that low power red laser light (LPRLL) is capable of affecting cellular processes in the absence of significant thermal effect. The objective of the present study was to determine the effect of LPRLL on proliferation of fetal cardiomyocytes in vitro and on the expression of proangiogenic genes, transforming growth factor-beta (TGF-beta), and vascular endothelial growth factor (VEGF). STUDY DESIGN/MATERIALS AND METHODS: All cell cultures were irradiated with single-dose LPRLL using a He-Ne continuous wave laser (632 nm) with different doses. The effect of LPRLL on new DNA synthesis was studied by 3H thymidine-incorporation assay. VEGF and TGF-beta expression by cardiomyocytes was studied by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: We observed that a dose-dependent increase in cardiomyocytes proliferation can be obtained with LPRLL and that there is a significant increase in VEGF and TGF-beta mRNA expression by cardiomyocytes. CONCLUSIONS: These data may have significant importance leading to the establishment of new methods for myocardial photoangiogenesis and photoregeneration as well as in vitro proliferation of cardiac myocytes