[Effect of hyperthermia on protein synthesis in monolayer and suspension cultures of mouse L cells].

Changes in protein synthesis that occurred under the influence of heat shock (HS) in monolayer (L929) and suspension (LS) mouse cell cultures were studied. The rates of protein synthesis determined as 35S-methionine incorporations were seen reduced from the initial level up to 40-60 and 6-13% after HS at 42 and 44 degrees C, respectively. Simultaneously the rate of actin and tubulin syntheses decreased, the decrease being more pronounced in LS cells. According to electrophoresis and autoradiography data, after hyperthermia both the cell cultures were able to synthesize heat shock proteins (HSP), primarily HSP70. After a 40 min HS towards L929 and LS cells at 43 degrees C, the shares of their HSP70 bands in the total label loaded on the gel constituted, resp., 8.8 and 5.4%. The data suggest that L929 cells, with their synthetic activity lower than in LS cells, appear more resistant to HS and are able eventually to synthesize larger amounts of HSP70, compared to the latter.