Development of cytochrome-c oxidase activity in rat heart: downregulation in newborn rats

Cell Biochem Biophys. 2005;43(1):87-94. doi: 10.1385/CBB:43:1:087.

Abstract

Cytochrome-c oxidase (COX) activity of the rat heart was two- to sevenfold activated when the membrane integrity was disrupted by hypotonic swelling, freezing-thawing, or a detergent, indicating that a large portion of COX capacity in intact mitochondria is not active. The effect of detergent was tested in heart mitochondria isolated from 1-, 5-, 15-, 29-, and 60-d-old rats; activation by detergent was up to 20-fold in 1-d-old animals, whereas in mitochondria from 60-d-old rats it was only 7-fold. Our data indicate that the rat heart exhibits significant developmental changes dependent on downregulation of COX activity in the neonatal period.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / drug effects
  • Aging / metabolism*
  • Animals
  • Animals, Newborn
  • Cells, Cultured
  • Detergents / administration & dosage
  • Down-Regulation / drug effects
  • Electron Transport Complex IV / metabolism*
  • Enzyme Activation / drug effects
  • Gene Expression Regulation, Developmental / drug effects
  • Gene Expression Regulation, Developmental / physiology*
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Enzymologic / physiology*
  • Heart / drug effects
  • Male
  • Mitochondria, Heart / drug effects
  • Mitochondria, Heart / enzymology*
  • Myocardium / enzymology*
  • Rats
  • Rats, Wistar

Substances

  • Detergents
  • Electron Transport Complex IV