Objective   To establish stress adaptaion model of mouse fibroblast cell line NIH-3T 3, and to provide a group of parallel object for stress adaptation research.To explore the function and mechanism of HSP90 in stress adaptation.

  Methods   Astress-adapted cell model was established by thermal preconditioning(42℃, 20 min).Adaptation situation was evaluated by the membrane injury(To measure the activity of lactate dehydrogenase in super natant by automatic biochemistry analyzer), damage of DNA(To measure the PIcontent pent rating into DNAby FCM)and th changes of cell mor pho logy.HSP90 content and location were deteced by immunocytochemistry.

  Results   Combining the membr ane injury and HSP90 synthesis immediately after heat stress, 6 h after thermal preconditioning was confirmed the ideal stress pro tection time.When cells faced heat sress 6 h after thermal preconditiong, the membrane injury, damage of DNAand the changes of cell morphology were alleviated co mpared withe control group which was heated without precondit ioning.Cellular HSP90 contets decreased immediately after heat stress(44 e, 40 min).HSP90 lo cated in cytoplasm under physiolog ical situat ion and were recruited intonucleolus under stress condiion.

  Conclusion   Thermal preconditioning may promote the relocat ion of HSP90 under stress condition.Cellular stress adaptation was established by NIH-3T 3 cell line thermal preconditioning.Stress prodection of HSP90 was confirmed in this model.The effect of high-level HSP 90 on cell may show pr otection under severe cirumstance, through HSP90 relocation and pr otectiong the vital proteins in stress signal transduction pathw ay.