抄録
The effect of light on calcium uptake by U937 cells was studied using 45Ca radiotracer techniques. Cells were treated with light while suspended in phosphate buffered saline, and the effects of variation in energy density, pulse frequency and wavelength investigated. The results showed that calcium uptake by the cells was dependent upon the energy density of the light source. Calcium uptake increased from 0 to 4 J/cm2 but then declined steadily as the energy density was increased up to 16 J!cm2, remaining at this level which was not significantly different from the control level, as the energy density was increased up to 32 J/cm2, the maximum tested. Calcium uptake was also shown to be both frequency- and wavelength-dependent. The most effective of the frequencies tested were in the range 16-36.48 Hz, The most effective of the wavelengths tested were 660, 820 and 870 nm. The alteration in intracellular calcium levels in response to exposure to light therapy may have considerable biological and clinical significance, since calcium ions act as second messengers in many forms of cell activity, including synthesis, secretion and intracellular communication.
