Expression of BiP in rat splenic macrophages with mild heat stress

AIM: To investigate the role of mild heat stress towards the immunological function of splenic macrophages and significance of BiP protein expression.METHODS: Primary cultured splenic macrophages were prepared and placed in 41 ℃ thermostat for thermal stress and restored to 37 ℃ after an hour. Heat stressed macrophages were separated into groups at time points of 0 min, 30 min, 60 min, 120 min and 180 min, and their BiP mRNA and BiP protein expressions were detected. At the same time, the phagocytic function, cytotoxicity and chemotaxis of the macrophages were detected.RESULTS: After heat stress, the expressions of BiP mRNA and BiP protein in splenic macrophages remarkably increased, and reached to peak after 30-60 min, still remained higher than control group after 120 min and restored to normal level after 180 min. At the same time, mild heat stress enhanced the phagocytotic, cytotoxicity and chemotactic activities of splenic macrophages, and reached to peak after 60 min then gradually decreased.CONCLUSION: The expression of BiP protein is enhanced after mild heat stress, synchronous changes happen both in BiP protein expression and cellular function. There is close relation between BiP protein expression and increased functions of splenic macrophages induced by mild heat stress.