INCREASE IN CYTOSOLIC AND MITOCHONDRIAL PROTEIN-SYNTHESIS IN RAT HEPATOCYTES IRRADIATED IN-VITRO BY HE-NE-LASER

In order to gain an insight into the mechanism of cell photostimulatio n by laser light, protein synthesis was measured in hepatocytes irradi ated with a low-power, continuous-wave He-Ne laser (fluence, 0.24 J cm (-2), fluence rate, 7 and 12 mW cm(-2)). As a result of irradiation, t he rate and amount of S-35-methionine incorporated into newly synthesi zed proteins increased, as demonstrated by gel electrophoresis and qua ntitative analysis of labelled protein bands. The stimulation of prote in synthesis was fluence dependent, with a maximum stimulation at 0.24 J cm(-2) for both Auence rates (12 and 7 mW cm(-2)). Both cytosolic a nd mitochondrial protein synthesis increased as a result of irradiatio n, as demonstrated by the measurement of hepatocytes previously treate d with chloramphenicol and cycloheximide respectively. An initial inve stigation showed that stimulation of protein synthesis also occurred i n hepatocytes irradiated with a non-coherent radiation source (fluence , 0.24 J cm(-2)).