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Aging reduces postischemic recovery of coronary endothelial function
M Amrani1, A H Chester, J Jayakumar
1Department of Cardiothoracic Surgery, National Heart and Lung Institute, Harefield Hospital, United Kingdom.
The Journal of Thoracic and Cardiovascular Surgery
|January 1, 1996
Summary
Aging impairs nitric oxide release from coronary endothelium after ischemia, while vascular smooth muscle function remains unaffected. This age-related decline impacts heart recovery, particularly in transplantation contexts.
Area of Science:
- Cardiovascular Physiology
- Aging Research
- Endothelial Function
Background:
- The aging process significantly alters cardiac function.
- Age-related changes in coronary endothelial and vascular smooth muscle function under ischemic conditions are not fully understood.
- Investigating age-related resistance to ischemia is crucial for understanding cardiovascular health.
Purpose of the Study:
- To determine if age affects the resistance of coronary endothelial and vascular smooth muscle function to ischemia.
- To assess the impact of aging on nitric oxide release and vascular smooth muscle responsiveness post-ischemia.
- To evaluate age-related functional changes in the context of organ transplantation.
Main Methods:
- Four groups of rats (1, 5, 15, 26 months) underwent 4-hour cardioplegic arrest at 4°C.
- Post-ischemic basal and stimulated nitric oxide release were measured using L-monomethylarginine and 5-hydroxytryptamine.
- Vascular smooth muscle function was assessed via endothelium-independent vasodilation with glyceryl trinitrate.
Main Results:
- Both basal and stimulated nitric oxide release from the endothelium significantly diminished with age post-ischemia (p < 0.05).
- Vascular smooth muscle function, assessed by response to glyceryl trinitrate, showed no significant age-related difference (p = not significant).
- The recovery of nitric oxide release, but not vascular smooth muscle function, decreased with age in a transplantation-mimicking protocol.
Conclusions:
- Coronary endothelial nitric oxide release capacity declines with age following ischemic events.
- Vascular smooth muscle responsiveness to vasodilators is preserved in aged hearts despite ischemia.
- Age-related endothelial dysfunction, specifically impaired nitric oxide release, may compromise post-ischemic cardiac recovery and transplantation outcomes.