Date of Award
Master of Science
Dr. Earl Noble
Dr. Greg Marsh
Exercise (EX) and heat-shock (HS) both lead to increased myocardial content of the cardioprotective inducible isoform of the 70 kDa heat shock protein, (Hsp70). Twenty- four hours after HS, myocardial Hsp70 is localized within blood vessels, indicating a cell-type specific response to this stress. The objective of the current study was to determine whether a similar localization of myocardial Hsp70 occurs post-EX. Adult male Sprague Dawley rats were randomized into control (CON), EX (60 min treadmill running, 30 m∕min) or HS (42°C, 15 min) groups. EX group was further divided into an acute exercise bout and a 5 day training group. Left ventricles (LV) were harvested at 30 min and 24 h post-treatment and analyzed for Hsp70 by both western blotting and confocal immunofluorescence microscopy. Both HS and EX resulted in significant increases in Hsp70 in LV homogenates. Twenty-four h post-EX and HS, confocal microscopy revealed a striking increase in localization of Hsp70 in smooth muscle of the larger blood vessels within the myocardium. Hsp70 was evident in the endothelium of hearts from all HS animals whereas it was observed in endothelium of only those EX animals that reached higher (40.5oC) exercise temperatures. These data support previous findings with HS and suggest that the myocardial increases in Hsp70 associated with exercise are also primarily limited to the vasculature. Differences in the models appear to be largely due to temperature difference, suggesting that heat may be the primary stimulus for the exercise induced response.
Wolff, Steven M., "EXERCISE INDUCES HSP70 IN THE VASCUALTURE OF THE MYOCARDIUM" (2008). Digitized Theses. 4311.