Heterogeneous ageing of skeletal muscle microvascular function

Area of Science:

• Physiology
• Aging Research
• Exercise Science

Background:

• Skeletal muscle blood flow distribution changes with age.
• These age-related alterations are linked to muscle-specific changes in arteriolar function.
• Functional adaptations in resistance arterioles differ between oxidative and glycolytic muscles.

Purpose of the Study:

• To investigate age-induced changes in skeletal muscle arteriolar function.
• To understand how these changes differ in oxidative versus glycolytic muscles.
• To determine the effects of exercise training on age-related microvascular dysfunction.

Main Methods:

• Analysis of arteriolar morphology and signaling pathways in different muscle types.
• Assessment of endothelial and vascular smooth muscle function.
• Evaluation of the impact of late-life exercise training on microvascular function.

Main Results:

• Age-related endothelial dysfunction in skeletal muscle arterioles is muscle-specific.
• Oxidative muscle arterioles show nitric oxide signaling loss, while glycolytic muscle arterioles exhibit alterations in both nitric oxide and prostanoid signaling.
• Late-life aerobic exercise training reverses age-related microvascular dysfunction and restores vascular function.

Conclusions:

• Age-induced changes in skeletal muscle blood flow are heterogeneous and depend on muscle fiber type.
• Exercise training is a potent intervention for reversing age-related microvascular dysfunction.
• Restoration of muscle blood flow patterns and vascular function is achievable even with exercise initiated at an advanced age.