Nd-YAGレーザーのミトコンドリア呼吸活性に対する影響 (レーザーサーミアの作用機序に関する考察)

抄録

Recent morphological investigations have revealed that there are severe structural changes in mitochondria after Nd-YAG laserthermia.
The purpose of this study was to evaluate biochemical influences of Nd-YAG laser upon mitochondria. methods The mitochondria was isolated from anesthetized Wister rat liver. Then Nd-YAG laser were irradiated to the suspension at 100, 400, 900mW for 20min. (40, 150, 340J/cm2) respectively. After irradiation respiratory control ratio (RCR: Chance's state3/state4) of each mitochondrial suspension was measured by the oxygraph. And proton Adenosine Triphosphatase (proton ATPase) activity was also measured by fluorometric assay.
To compare the influences of Nd-YAG upon mitochondria with those of the other wavelength laser, Argon ion laser was selected and irradiated at the same condition. results ‹Nd-YAG› Significant decreases of RCR data were observed in Nd-YAG laser groups. But proton ATPase activities were almost preserved in these groups. Especially, after 100mW irradiation, ATPase activity was significantly elevated. It suggests the mitochondrial respiratory activity was photostimulated by low power Nd-YAG laser. ‹Argon ion laser› As regards RCR data, the results were almost similar to Nd-YAG. But according to the increase of laser power, ATPase activities were decreased. During laser irradiation the temperature of the suspension elevated less than 5°C, and they may not cause thermal damage for mitochondria. conclusions The results suggest that Nd-YAG laser light inhibits mitochondrial respiratory activity at 400, 900mW irradiation, but at lower power as 100mW, Nd-YAG laser may cause some acceleration of mitochondrial respiration by photostimulation effect. Also it is recognized different wavelength laser irradiation may cause different effects on mitochondrial respiration.