Ischemic preconditioning depends on age and gender.
The goal of this study was to determine if an ischemic preconditioning (IPC) protocol improved post-ischemic functional recovery of female mouse hearts. A previous study found that IPC did not occur in hearts from 10-week-old females. We studied Langendorff-perfused hearts from both 10- and 18-week-old mice (males and females). Hearts were subjected to 45 min ischemia and 45 reperfusion (I/R); IPC involved pretreatment with 3 min ischemia. We measured hemodynamics, infarct size and levels of the phosphorylated prosurvival kinase Akt (p-Akt). Similar to a previous study, for 10- week-old mice we found that the IPC protocol appreciably improved recovery of LV developed pressure (LVDP) for hearts from males but not females. However, for 18-week-old mice we found that the IPC protocol doubled the recovery of LVDP for both males and females. For both ages, hearts from females had greater recovery of LVDP and higher levels of p-Akt compared to males.


CONCLUSIONS
These findings are consistent with growing evidence that preconditioning induced by ischemia or other interventions can occur in hearts from females. However, for hearts from females, preconditioning depends on age. Moreover, consistent with previous studies, hearts from females have greater inherent resistance to ischemic injury, possibly involving increased signaling via p-Akt.
Turcato
S
S
University of California, San Francisco, VA Medical Center, Cardiology Division 111C, 4150 Clement St, San Francisco, CA 94121, USA.
Turnbull
L
L
Wang
G-Y
GY
Honbo
N
N
Simpson
P C
PC
Karliner
J S
JS
Baker
A J
AJ
D000367:Age Factors; D000375:Aging; D000818:Animals; D015153:Blotting, Western; D003326:Coronary Circulation; D005260:Female; D066298:In Vitro Techniques; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017202:Myocardial Ischemia / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012727:Sex Characteristics; D012737:Sex Factors; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
D051057:Proto-Oncogene Proteins c-akt