The myocardial heat shock response following sodium salicylate treatment.
In cultured cells, salicylate has been shown to potentiate the induction of Hsp72 so that a mild heat stress (40 degrees C) in the presence of salicylate induces an Hsp72 response that is similar to a severe heat stress (42 degrees C). To determine whether salicylate can potentiate the myocardial Hsp70 response in vivo and confer protection from an ischemic stress, male Sprague-Dawley rats (250-300 g) were placed into 5 groups: (1) control, (2) salicylate only (400 mg/kg), (3) mild heat stress (40 degrees C for 15 minutes), (4) mild heat stress plus salicylate, and (5) severe heat stress (42 degrees C for 15 minutes). Twenty-four hours following salicylate treatment and/or heat stress, animals were anesthetized, their hearts rapidly isolated, and hemodynamic function evaluated using the Langendorff technique. Hsp72 content was subsequently assessed by Western blotting. Although salicylate in combination with a mild heat stress induced heat shock factor activation, only the hearts from severely heat-stressed animals (42 degrees C) demonstrated a significantly elevated myocardial Hsp72 content and a significantly enhanced postischemic recovery of left ventricular developed pressure and rates of contraction and relaxation. These results support the role for Hsp72 as a protective protein and suggest that neither salicylate treatment alone nor salicylate in combination with a mild heat stress potentiates the myocardial Hsp72 response.
Locke
M
M
Faculty of Physical Education and Health, University of Toronto, Ontario, Canada. marius.locke@utoronto.ca
Atance
J
J
D000818:Animals; D001794:Blood Pressure; D003326:Coronary Circulation; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis; D018869:Heat-Shock Response / Q000187:drug effects*; D006439:Hemodynamics; D066298:In Vitro Techniques; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012980:Sodium Salicylate / Q000494:pharmacology*; D016276:Ventricular Function
D018840:HSP70 Heat-Shock Proteins; D012980:Sodium Salicylate