ACTIVATION OF MITOCHONDRIAL-DNA REPLICATION BY HE-NE-LASER IRRADIATION

To gain further insight into the effect of He-Ne laser irradiation on the mitochondrial biosynthetic apparatus, DNA synthesis was measured in mitochondria, mitoplasts and mitochondrial matrix fraction irradiated with low power continuous wave He-Ne laser (energy dose 5 Joules/cm2; laser power 12 mW). As a result of irradiation, the amount of α-[32P]dATP incorporated in acid insoluble materials was found to increase. Electrophoretic analysis of in vitro synthesised DNA purified from mitochondria, mitoplasts and matrix fraction shows an increase of 50-60% of DNA synthesis in the irradiated samples. These data show that He-Ne laser stimulates the replication of mitochondrial DNA in both intact organelles and soluble matrix fraction, thus suggesting an interaction of laser light with matrix soluble molecule/s. © 1993 Academic Press, Inc.