Figure 1

Aging hearts release higher levels of HSP27. A) Hearts from adult (4–6 months) and aging (18–24 months) mice were subjected to global ischemia/reperfusion (I/R: I 20 min/R 60 min). Coronary effluent is collected before ischemia and at 0–5 min or 55–60 min of reperfusion, and heat shock protein 27 (HSP27) was analyzed. HSP27 release occurred primarily in early reperfusion, and aging hearts released higher levels of HSP27. Data are expressed as mean ± SE. n = 8; ^aP < 0.05 versus baseline; ^bP < 0.05 versus time-matched adult I/R. B) Cardiac microvascular endothelial cells isolated from adult and aging mice were subjected hypoxia (95% nitrogen and 5% oxygen) for 1 h. A representative image shows that HSP27 distribution is changed from a diffused pattern to a granular pattern following hypoxia and that HSP27 is localized on the cell membranes. ELISA data show that cells from aging hearts release a greater amount of HSP27 during hypoxia. Data are expressed as mean ± SE. n = 5; ^aP < 0.05 versus normoxia; ^bP < 0.05 versus adult hypoxia.