Abstract

Heat Shock Proteins (HSPs) are chaperone proteins that are produced as a result of environmental and physiological stress (heat, ischemia and chemicals). HSPs work to limit the severity of stresses inflicted on the body. HSP70 and HSP90 are two proteins of particular interest. HSP70 is responsible for preventing protein aggregation that could cause cell death. HSP70 also functions as an inhibitor in the apoptotic pathway, another cause of cellular death. Both HSP70 and HSP90 function as a chaperone in the folding of newly synthesized proteins and are involved in the activation of the anti-inflammatory response. Increased HSP70 and HSP90 production has been correlated with an increased likelihood of survivability of tissue exposed to heat or ischemic conditions. In this experiment four rats were subj ected to seven days of heat acclimation at 31º C while four additional rats were maintained at 22ºC as a control. The hearts of the rats were then removed, homogenized, and centrifuged; then supernatant as well as pellets were tested for levels of HSP70 and HSP90 using Western blotting and antibody labeling. The HSP90 antibodies failed to provide protein stains. The experimental data obtained from these Western blots failed to show a significant increase in HSP70 production in heat- acclimated rat hearts as compared to control (non-heat-acclimated) rat hearts in neither the supernatant or pellet samples. However, the data did show a tendency for increased HSP70 in the heat-acclimated rats as compared to the control rats in both the supernatant and pellet samples.