Impaired microcirculatory function, mitochondrial respiration, and oxygen utilization in skeletal muscle of claudicating patients with peripheral artery disease

Song Young Park, Elizabeth J. Pekas, Cody P. Anderson, Tyler N. Kambis, Paras K. Mishra, Molly N. Schieber, Te Sean K. Wooden, Jonathan R. Thompson, Kyung Soo Kim, Iraklis I. Pipinos

Research output: Contribution to journalArticlepeer-review

Abstract

Peripheral artery disease (PAD) is an atherosclerotic disease that impairs blood flow and muscle function in the lower limbs. A skeletal muscle myopathy characterized by mitochondrial dysfunction and oxidative damage is present in PAD; however, the underlying mechanisms are not well established. We investigated the impact of chronic ischemia on skeletal muscle microcirculatory function and its association with leg skeletal muscle mitochondrial function and oxygen delivery and utilization capacity in PAD. Gastrocnemius samples and arterioles were harvested from patients with PAD (n = 10) and age-matched controls (Con, n = 11). Endothelium-dependent and independent vasodilation was assessed in response to flow (30 μL min-1), acetylcholine, and sodium nitroprusside (SNP). Skeletal muscle mitochondrial respiration was quantified by high-resolution respirometry, microvascular oxygen delivery, and utilization capacity (tissue oxygenation index, TOI) were assessed by near-infrared spectroscopy. Vasodilation was attenuated in PAD (P < 0.05) in response to acetylcholine (Con: 71.1 ± 11.1%, PAD: 45.7 ± 18.1%) and flow (Con: 46.6 ± 20.1%, PAD: 29.3 ± 10.5%) but not SNP (P = 0.30). Complex I + II state 3 respiration (P < 0.01) and TOI recovery rate were impaired in PAD (P < 0.05). Both flow and acetylcholine-mediated vasodilation were positively associated with complex I + II state 3 respiration (r = 0.5 and r = 0.5, respectively, P < 0.05). Flow-mediated vasodilation and complex I + II state 3 respiration were positively associated with TOI recovery rate (r = 0.8 and r = 0.7, respectively, P < 0.05). These findings suggest that chronic ischemia attenuates skeletal muscle arteriole endothelial function, which may be a key mediator for mitochondrial and microcirculatory dysfunction in the PAD leg skeletal muscle. Targeting microvascular dysfunction may be an effective strategy to prevent and/or reverse disease progression in PAD.

Original languageEnglish (US)
Pages (from-to)H867-H879
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume322
Issue number5
DOIs
StatePublished - May 2022

Keywords

  • chronic ischemia
  • endothelial dysfunction
  • microvascular dysfunction
  • peripheral artery disease

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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