Effects of Low-power Laser Irradiation on Cell Locomotion in Protozoa¶

Abstract

Low-power lasers are commonly used in human medicine for treatment of various pathological conditions, but mechanisms of their healing effects are still poorly understood. The results of this study provide information related to these effects at the cellular level. Two different protozoan species, Euglena gracilis and Tetrahymena thermophila, were used to study changes in locomotion behavior in response to low-power lasers. The cells were irradiated at 830 and 650 nm generated by a semiconductor laser (99 J/cm2, 360 mW) and a laser pointer (0.75 J/cm2, 5 mW), respectively, and their locomotion was recorded by a TV camera and analyzed using computer software. Exposure to laser light, regardless of the wavelength, resulted in increased cell velocity in both species (P <0.001). Exposure to 650 nm produced an equal increase in median cell velocity in both E. gracilis (19.0%) and T. thermophila (18.2%), and some increase persisted in the postirradiation 30 s period. Irradiation by the 830 nm laser resulted in a markedly higher response in Tetrahymena (29.4%) than in Euglena (15.2%), and the two median values remained increased after irradiation was discontinued. Different reactions found in the species studied and some mechanisms underlying the response of cells to radiation are discussed.

A Novel 785-nm Laser Diode-Based System for Standardization of Cell Culture Irradiation

“…1 LLLT using far-red to near-infrared (NIR) spectra has been found to modulate different biological processes in cell cultures such as: increasing ATP synthesis, 2 producing analgesic effects, 3 accelerating tissue healing, 4,5 and triggering acid nucleic production, increasing cell proliferation and metabolism. [5][6][7] Some specific types of laser can also stimulate fibroblasts to synthesize and deposit collagen matrix.…”

“…1 LLLT using far-red to near-infrared (NIR) spectra has been found to modulate different biological processes in cell cultures such as: increasing ATP synthesis, 2 producing analgesic effects, 3 accelerating tissue healing, 4,5 and triggering acid nucleic production, increasing cell proliferation and metabolism. [5][6][7] Some specific types of laser can also stimulate fibroblasts to synthesize and deposit collagen matrix. [8][9][10] A number of in vitro investigations using a wide range of cell cultures have provided different data concerning cell proliferation 11,12 and differentiation, 13 DNA and bone protein synthesis, 1,[14][15][16] and bone tissue formation without genotoxic or cytotoxic damage.…”

Persistencia de los Efectos del Láser Infrarrojo 6 J/cm² en Hepatocitos de Rata

“…Estos resultados son coincidentes con los descritos por distintos investigadores, así Baibekov et al (1992) los cuales evidencian incremento en los volúmenes tanto nucleares como nucleolares, igualmente Marques et al (2004) idénticos hallazgos en fibroblastos, Koutna et al (2003) comunicando activa síntesis de RNA producto de activa transcripción y Tamietti et al (2007) quienes informan además de una acentuada condensación de la cromatina.…”

Estudio Morfométrico del Efecto de Láser Infrarrojo 16 J/cm2 sobre Hepatocitos de Rata

“…El análisis de los resultados entre hepatocitos irradiados con dosis de 8 y 16 J/cm 2 revela que existen marcadas diferencias entre las fracciones volumétricas de componentes celulares determinantes de funcionalidad celular e involucrados en síntesis proteica, cuantificación que demuestra claramente que dosis de 8 J/cm 2 logra un óptimo de estimulación para lograr alta funcionalidad, mientras que 16 J/cm 2 evidencia notable inhibición de dicha funcionalidad, concluyéndose entonces que los efectos de dosis específicas de radiación infrarroja provoca en los hepatocitos una drástica transformación en sus componentes y por ende en su funcionalidad representando el efecto de estas estimulaciones sobre este tipo celular de elevado metabolismo. (Kreisler et al, 2003; Khadra et al, 2005) las concentraciones de calcio citosólico (Cohen et al, 1998;Koutná et al, 2003) y la actividad de variadas enzimas (Cieslar et al, 1995;Kao & Sheen, 2003).…”