Apocynin improves diaphragmatic function after endotoxin administration

G. Supinski, D. Stofan, D. Nethery, L. Szweda, A. Dimarco

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Free radicals are known to play an important role in modulating the development of respiratory muscle dysfunction during sepsis. Moreover, neutrophil numbers increase in the diaphragm after endotoxin administration. Whether or not superoxide derived from infiltrating white blood cells contributes to muscle dysfunction during sepsis is, however, unknown. The purpose of the present study was to examine the effect of apocynin, an inhibitor of the superoxide-generating neutrophil NADPH complex, on endotoxin-induced diaphragmatic dysfunction. We studied groups of rats given saline, endotoxin, apocynin, or both endotoxin and apocynin. Animals were killed 18 h after injection, a portion of the diaphragm was used to assess force generation, and the remaining diaphragm was used for determination of 4-hydroxynonenal (a marker of lipid peroxidation) and nitrotyrosine levels (a marker of free radical-mediated protein modification). We found that endotoxin reduced diaphragm force generation and that apocynin partially prevented this decrease [e.g., force in response to 20 Hz was 23 ± 1 (SE), 12 ± 2, 23 ± 1, and 19 ± 1 N/cm2, respectively, for saline, endotoxin, apocynin, and endotoxin/apocynin groups; P < 0.001]. Apocynin also prevented endotoxin-mediated increases in diaphragm 4-hydroxynonenal and nitrotyrosine levels (P < 0.01). These data suggest that neutrophil-derived free radicals contribute to diaphragmatic dysfunction during sepsis.

Original languageEnglish (US)
Pages (from-to)776-782
Number of pages7
JournalJournal of Applied Physiology
Volume87
Issue number2
StatePublished - Aug 18 1999

Fingerprint

Endotoxins
Diaphragm
Free Radicals
Sepsis
Neutrophils
Superoxides
Respiratory Muscles
acetovanillone
NADP
Lipid Peroxidation
Leukocytes
Muscles
Injections
Proteins

Keywords

  • Diaphragm
  • Free radicals
  • Respiratory muscles
  • Skeletal muscle

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Supinski, G., Stofan, D., Nethery, D., Szweda, L., & Dimarco, A. (1999). Apocynin improves diaphragmatic function after endotoxin administration. Journal of Applied Physiology, 87(2), 776-782.

Apocynin improves diaphragmatic function after endotoxin administration. / Supinski, G.; Stofan, D.; Nethery, D.; Szweda, L.; Dimarco, A.

In: Journal of Applied Physiology, Vol. 87, No. 2, 18.08.1999, p. 776-782.

Research output: Contribution to journalArticle

Supinski, G, Stofan, D, Nethery, D, Szweda, L & Dimarco, A 1999, 'Apocynin improves diaphragmatic function after endotoxin administration', Journal of Applied Physiology, vol. 87, no. 2, pp. 776-782.
Supinski G, Stofan D, Nethery D, Szweda L, Dimarco A. Apocynin improves diaphragmatic function after endotoxin administration. Journal of Applied Physiology. 1999 Aug 18;87(2):776-782.
Supinski, G. ; Stofan, D. ; Nethery, D. ; Szweda, L. ; Dimarco, A. / Apocynin improves diaphragmatic function after endotoxin administration. In: Journal of Applied Physiology. 1999 ; Vol. 87, No. 2. pp. 776-782.
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