Fig. 1.

Chronic heat stress causes increases in phosphorylation of p38MAPK and Akt, and induces enhancement of protein levels of Hsp70 and MnSOD in V79 fibroblasts. Cells were treated with chronic heat stress for a period of 4 weeks. Thermal stress was applied at 43°C for 15 min in culture every alternate day. Cells were harvested after either a 2-week or a 4-week experimental period. Western blotting of the cell lysates was performed. The Western blots are representative of two–three independent experiments. The numbers on the top of the blots are indicative of the respective band densities when the control is normalized to 10. Cells were either left untreated (Vctrl), treated with chronic heat stress (V2WkHS) for 2 weeks, or treated with chronic heat stress (V4WkHS) for 4 weeks. Details of the experimental procedure are given in the materials and methods section