Acute effects of hydrogen peroxide on skeletal muscle microvascular oxygenation from rest to contractions

• Published in: Journal of applied physiology (1985) 2011-05, Vol.110 (5), p.1290-1298
• Main Authors: HIRAI, Daniel M, COPP, Steven W, SCHWAGERL, Peter J, MUSCH, Timothy I, POOLE, David C
• Format: Article
• Language: English
• Subjects: Anesthesia; Animals; Biological and medical sciences; Effects; Fundamental and applied biological sciences. Psychology; Hydrogen peroxide; Hydrogen Peroxide - pharmacology; Kinetics; Male; Microcirculation - drug effects; Microcirculation - physiology; Microvessels - drug effects; Microvessels - physiology; Muscle Contraction - drug effects; Muscle Contraction - physiology; Muscle, Skeletal - blood supply; Muscle, Skeletal - drug effects; Muscle, Skeletal - physiology; Musculoskeletal system; Oxygen; Oxygen - metabolism; Oxygen Consumption - physiology; Rats; Rats, Sprague-Dawley; Rest - physiology; Rodents
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.01489.2010

Reactive oxygen species, such as hydrogen peroxide (H(2)O(2)), exert a critical regulatory role on skeletal muscle function. Whether acute increases in H(2)O(2) modulate muscle microvascular O(2) delivery-utilization (Qo(2)/Vo(2)) matching [i.e., microvascular partial pressure of O(2) (Pmv(O(2)))] at rest and following the onset of contractions is unknown. The hypothesis was tested that H(2)O(2) treatment (exogenous H(2)O(2)) would enhance Pmv(O(2)) and slow Pmv(O(2)) kinetics during contractions compared with control. Anesthetized, healthy young Sprague-Dawley rats had their spinotrapezius muscles either exposed for measurement of blood flow (and therefore QO(2)), VO(2), and Pmv(O(2)), or exteriorized for measurement of force production. Electrically stimulated twitch contractions (1 Hz, ~7 V, 2-ms pulse duration, 3 min) were evoked following acute superfusion with Krebs-Henseleit (control) and H(2)O(2) (100 μM). Relative to control, H(2)O(2) treatment elicited disproportionate increases in QO(2) and VO(2) that elevated Pmv(O(2)) at rest and throughout contractions and slowed overall Pmv(O(2)) kinetics (i.e., ~85% slower mean response time; P < 0.05). Accordingly, H(2)O(2) resulted in ~33% greater overall Pmv(O(2)), as assessed by the area under the Pmv(O(2)) curve (P < 0.05). Muscle force production was not altered with H(2)O(2) treatment (P > 0.05), evidencing reduced economy during contractions (~40% decrease in the force/VO(2) relationship; P < 0.05). These findings indicate that, although increasing the driving force for blood-myocyte O(2) flux (i.e., Pmv(O(2))), transient elevations in H(2)O(2) impair skeletal muscle function (i.e., reduced economy during contractions), which mechanistically may underlie, in part, the reduced exercise tolerance in conditions associated with oxidative stress.