Mitochondrial respiration after sepsis and prolonged hypoxia.

Journal Article (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

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajplung.1998.275.1.L139

Language

  • eng

Conference Location

  • United States