Age-related changes in ischemic tolerance in male and female mouse hearts.

Aging is associated with reduced tolerance to ischemic insult, and genesis of this intolerant phenotype is poorly understood. We characterized effects of aging and gender on cardiovascular function and cell damage during 20 min ischemia and 60 min reperfusion in isolated hearts from young adult (2-4 months), mature adult (8 months), middle-aged (12 months), aged (18 months), and senescent (24-28 months) C57/Bl6 mice. Aging substantially impaired recovery of ventricular contractility, with this change primarily evident within 12 months of age.

Ischaemic tolerance in aged mouse myocardium: the role of adenosine and effects of A1 adenosine receptor overexpression.

The genesis of the ischaemia intolerant phenotype in aged myocardium is poorly understood. We tested the hypothesis that impaired adenosine-mediated protection contributes to ischaemic intolerance, and examined whether this is countered by A1 adenosine receptor (A1AR) overexpression. Responses to 20 min ischaemia and 45 min reperfusion were assessed in perfused hearts from young (2-4 months) and moderately aged (16-18 months) mice.