S. Hirai

The difference of HSP72 induction in rat’s systemic organs after burn injury depends on burned body surface area

Abstract We have previously reported that in severely burned rats, the induction of 72-kD stress protein (HSP72) increased in various systemic organs. In this present study, in order to compare the stress response of systemic organs to burn injury of a smaller total body surface area with those of an extensive burn, we investigated the induction of 72-kD heat shock protein (HSP72) in various organs (brain, hypophysis, lung, heart, liver, pancreas, spleen, kidney, adrenal gland, and skeletal muscle) of burned rats. A dermal burn was developed on the skin by immersing the rats in hot water (90° C) for three seconds. At 0, 24 and 48 h after burn injury, the HSP72 induction of various organs was examined by Western blot analysis. In the single hind leg burn, the level of HSP72 did not increase at any time in all ten organs. In the double hind leg burn, at 48 h, the induction of HSP72 increased more than 1.5 fold compared to the control in the hypophysis (1.6 fold) and the heart (1.8 fold). These results indicate that the double hind leg burn causes a stress response in the hypophysis and the heart, while the single hind leg burn does not cause this stress response. In extensively burned rats, the degree of the stress response of the systemic organs to the burn injury depends on the burn size, and the intensity of “burn stress” to the systemic organs in a double or single hind leg burn is relatively small compared with those in extensive burns at the molecular level.