Abstract
Our clinical experience has shown that intractable gastric ulcers can be healed effectively by Nd: YAG laser phototherapy. One of the mechanisms is a destructive effect on the fibrous tissue of the ulcers by high power densities of laser radiation. The other is a specific effect on it of the wave lentgh. However, these mechanisms are still unclear. The pourpose of this study is to make clear a specificity of the wave length of Nd: YAG laser in biological effect.
Laser was radiated to the cultured canine hepatocytes in plastic culture dish at 50w of out put power, 5 second duration and 10cm of distance. Power densities were applied from 120 to 480 J/cm2 in this condition. The specific effect of the wave length was evaluated by the measurement of the viability of hepatocytes, the ability of 3H-thymidine and 14C-leucine up-takes after 24 hours of radiation.
Temperature in the culture dish rose to approximately average of 44°C during radiation. Viability of hepatocytes was 94+1%before radiation and was 9511% after radiation with 480J/cm2. The ability of up-take of the radioisotopes showed no remarkable changes in comparison with non radiation group.
These results suggest that the specific effect of the wave length is not essential on a healing of intractable ulcers in condition of usual clinical application of Nd: YAG laser.
