The Effect of Hene Laser (633 nm) Radiation on Intracellular Ca²⁺ Concentration in Fibroblasts

The increasing use of phototherapy (for example in wound healing) has led to a great interest in the mechanism of light-biosystem interaction. Therefore, recent observations on the enhancement of the proliferation of irradiated skin cells (fibroblasts and keratinocytes) by visible light are important to understand phototherapy at the cellular level. In the present communication we show that at the doses appropriate for enhanced fibroblast proliferation, HeNe irradiation produces transiently increasing calcium concentration in the target cells. Fibroblasts were irradiated with 1, 3 and 5 J/cm² HeNe (633 nm) laser and intracellular Ca²⁺ concentration ([Ca²⁺]i) in single cells was analyzed by Fluo-3/AM using a dynamic video imaging system with frame-grabbing soft ware. Such observations can explain photobiostimulation because of the well-known vital role played by calcium in important biological processes such as proliferation and exocytosis.