J Clin Laser Med Surg. 1991 Feb; 9(1): 35-41.

The biological effects of low power laser irradiation on cultivated rat glial and glioma cells.

Tsai JC, Kao MC.

Department of Surgery, College of Medicine, National Taiwan University Hospital, Taipei, R.O.C.

Two cell lines were used as models to investigate the biological effects resulting from irradiation by low power lasers. One was a well-established rat glial cell line (RBA-1) obtained from the dissociated culture of normal neonatal rat (JAR-2, F-51) brain tissue. The other was a rat C6 glioma cell line obtained from a propagated culture of rat glial tumor induced by N-nitrosomethylurea. Both of them showed relatively constant cellular morphological characteristics and had steady growth and proliferation in the monolayer system. In this study, the monolayer cell culture was exposed to irradiation by various lasers at low power density in various situations. These lasers with their low energy range are used conventionally in bioregulation and acupuncture, so that their output power primarily will not cause a significant elevation of temperature of the irradiated tissue. The effects on cellular morphology, proliferation, and other functional activities after various conditions of irradiation were studied. A biostimulatory effect was noted after He-Ne laser irradiation on C6 glioma cells and was dose related. A biostimulatory effect was noted also after IR (gallium-arsenide infrared) laser irradiation but was not dose related. No significant biostimulatory effects on RBA-1 cells were noted after exposure to the four types of lasers used in this study.