Mitochondrial respiration after sepsis and prolonged hypoxia.


Journal Article

Recently, marked oxygen dependence of respiration by isolated mitochondria after exposure to prolonged hypoxia has been described. Because mitochondrial oxygen-dependent respiration could significantly influence oxygen consumption during critical illness, we sought to confirm the oxygen-dependent behavior of mitochondria. We hypothesized that mitochondria isolated during sepsis would exhibit increased oxygen dependence. We isolated rat liver mitochondria 16 h after cecal ligation and puncture and found a 30-40% greater oxygen uptake compared with control rats under state 3 conditions. Mitochondria incubated in deoxygenated buffer were studied for oxygen dependence at 10-min intervals for 90 min. Mitochondrial respiration after reoxygenation was stable over a 60-min period of hypoxia for control rats and decreased slightly for septic rats (10-15%). State 3 respiration was 10% lower when mitochondria were reoxygenated at low (15-25 Torr) versus high (90-100 Torr) and low (10-15 Torr) versus intermediate (40-45 Torr) oxygen tension. Oxygen consumption with ascorbate+N, N, N', N'-tetramethyl-p-phenylenediamine was 20% lower at low versus high oxygen tension. No increase in oxygen dependence was observed during 1 h of hypoxic incubation. Our data indicate only a modest oxygen dependence of respiration between 10 and 100 Torr, which is similar for septic and control mitochondria. Additionally, oxygen dependence did not increase significantly during a 1-h hypoxic exposure for well-coupled mitochondrial preparations.

Full Text

Duke Authors

Cited Authors

  • Taylor, DE; Kantrow, SP; Piantadosi, CA

Published Date

  • July 1998

Published In

Volume / Issue

  • 275 / 1

Start / End Page

  • L139 - L144

PubMed ID

  • 9688945

Pubmed Central ID

  • 9688945

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajplung.1998.275.1.L139


  • eng

Conference Location

  • United States