title: Effect of low-intensity argon laser irradiation on mitochondrial respiration.
abstract: We studied influences of low-intensity argon laser irradiation at various wavelengths on mitochondrial respiration in vitro. Isolated guinea pig liver mitochondria were suspended in an isotonic buffer solution (pH 7.4, 37 degrees C). The mitochondrial suspension was introduced into a constant temperature reaction chamber in which an irradiation fiber, a thermocouple, an oxygen electrode, and a stirrer were installed. Under respiratory conditions of state 4, state 3, and uncoupled respiration, mitochondrial oxygen consumption was measured during low-intensity argon laser irradiations at 351nm, 458 nm, and 514.5 nm. The 351 nm and the 458 nm irradiations at 200 mW inhibited uncoupled respiration by 19% and 11%, respectively, and the irradiation at 351 nm inhibited state 3 respiration as well by 10%. In contrast, the 514.5 nm irradiation enhanced both state 3 and uncoupled respiration by 6-7%. Temperature reference experiments indicated that the thermal effect alone could not account for the effects of laser irradiation on mitochondrial oxygen consumption. These results suggest that the 351 nm and the 458 nm laser irradiation may injure the mitochondrial inner membrane, while the 514.5 nm laser irradiation may slightly promote the rate of ATP synthesis.
authors.affiliation: Department of Medical Engineering, National Defense Medical College, Saitama, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Morimoto
authors.forename: T
authors.initials: T
authors.lastname: Arai
authors.forename: M
authors.initials: M
authors.lastname: Kikuchi
authors.forename: S
authors.initials: S
authors.lastname: Nakajima
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D019297:2,4-Dinitrophenol; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000818:Animals; D001128:Argon; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D001728:Dicumarol / Q000494:pharmacology; D004140:Dinitrophenols / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D006358:Hot Temperature / Q000009:adverse effects; D007425:Intracellular Membranes / Q000528:radiation effects / Q000648:ultrastructure; D007834:Lasers; D008027:Light; D008293:Malates / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism* / Q000528:radiation effects*; D010084:Oxidation-Reduction / Q000528:radiation effects; D010101:Oxygen Consumption / Q000528:radiation effects*; D013347:Subcellular Fractions; D013386:Succinates / Q000378:metabolism; D019802:Succinic Acid; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D004140:Dinitrophenols; D008293:Malates; D013386:Succinates; D014475:Uncoupling Agents; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D000244:Adenosine Diphosphate; D001128:Argon; D001728:Dicumarol; C030298:malic acid; D000255:Adenosine Triphosphate; D019802:Succinic Acid; D019297:2,4-Dinitrophenol