A method for isolating lung mitochondria from rabbits, rats, and mice with improved respiratory characteristics
✍ Scribed by R. Kenneth Spear; Lawrence Lumeng
- Publisher
- Elsevier Science
- Year
- 1978
- Tongue
- English
- Weight
- 546 KB
- Volume
- 90
- Category
- Article
- ISSN
- 0003-2697
No coin nor oath required. For personal study only.
✦ Synopsis
Previous methods for isolating lung mitochondria, particularly from rabbits, have yielded preparations which exhibit low respiratory control ratios (RCRs). We now report a method for the isolation of lung mitochondria from rabbit, rat, and mouse with RCRs, ADP/O ratios, and rates of substrate oxidation comparable to those for liver mitochondria. These mitochondrial preparations fail to oxidize exogenously added NADH and exhibit RCRs, during succinate oxidation, which closely approximate those obtained with NADH-linked substrates. However, an otherwise latent Mg2+-stimulated ATPase activity can still be elicited when Mg*+ is added to the mitochondrial incubation medium. This ATPase activity is insensitive to oligomycin and atractyloside, indicating that the source is from contaminating endoplasmic reticulum. The pH and EDTA concentration for maximum substrate oxidation and RCR were found to be 7.2 and 0.1 mM, respectively. State 4 respiration was affected by pH and EDTA concentration while state 3 respiration appeared to be independent of these two factors over the ranges studied.