Diminished heat shock protein 70 mRNA induction in aged rat hearts after ischemia

Am J Physiol. 1994 Nov;267(5 Pt 2):H1795-803. doi: 10.1152/ajpheart.1994.267.5.H1795.

Abstract

Vulnerability of aged hearts to ischemia may be due to defects in protective mechanisms provided by heat shock proteins (HSPs). To determine whether there is a defect in the induction of HSPs by ischemia in old hearts, HSP72 and HSP73 (inducible and constitutive HSP70, respectively) mRNA induction was examined in young (2-mo-old; n = 36) and old (18-mo-old; n = 32) rat hearts. Transient (10- or 20-min) ischemia was applied by tightening a snare placed around left coronary arterial branches 3 days before examination to avoid the effect of operation on induction. HSP72 mRNA was induced markedly in young hearts after 10-min ischemia, peaked at 2 h, but was induced only slightly in old hearts. HSP73 mRNA was also induced in young hearts, peaked at 4 h, but was not induced in old hearts. The mRNAs were markedly induced in old hearts as well after 20-min ischemia, which was accompanied by the induction of HSP72 protein. Thus the age-related modulation of HSP72 and HSP73 mRNAs suggests a defective sensing mechanism for ischemia in old hearts.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / metabolism
  • Animals
  • Blotting, Northern
  • Gene Expression*
  • HSP70 Heat-Shock Proteins / biosynthesis*
  • Heart / growth & development
  • Male
  • Myocardial Ischemia / metabolism*
  • Myocardial Ischemia / pathology
  • Myocardial Ischemia / physiopathology
  • Myocardium / metabolism*
  • Myocardium / pathology
  • RNA, Messenger / biosynthesis*
  • Rats
  • Rats, Wistar
  • Reference Values
  • Time Factors

Substances

  • HSP70 Heat-Shock Proteins
  • RNA, Messenger