Evaluation of mitochondrial respiratory function in small biopsies of liver.
Mitochondrial respiratory function was studied in permeabilized pig liver biopsies. The cell membrane was permeabilized mechanically in tissue samples of 2-7 mg, for application of a standardized substrate/inhibitor titration protocol in high-resolution respirometry. Specific respirometric tests demonstrated complete plasma membrane permeabilization and accessibility of substrates to intact mitochondria. High respiratory adenylate control ratios and cytochrome c conservation in the tissue preparation were comparable or even better than in isolated mitochondria. Citrate synthase and cytochrome c oxidase activities remained at 85% of controls after up to 98 h storage of liver tissue at 0 degrees C in histidine-tryptophan-ketoglutarate solution. Multiple mitochondrial defects, however, were indicated after 48 h cold storage by the decline in respiratory capacity, which was lowered to a larger extent with complex I substrates compared to respiration with substrates for complex II or IV, measured in the absence of cytochrome c. After prolonged ischemia, the adenylate control ratio was significantly reduced, and cytochrome c depletion was detected by the stimulatory effect of cytochrome c. High-resolution respirometry allows the assessment of mitochondrial function in a few milligrams of permeabilized liver tissue, without isolation of mitochondria. This provides a basis for the analysis of mitochondrial function in human liver biopsies.
Kuznetsov
Andrey V
AV
Department of Transplant Surgery, D. Swarovski Research Laboratory, University Hospital Innsbruck, Anichstrasse 35, Innsbruck, A-6020, Austria.
Strobl
Daniela
D
Ruttmann
Elfriede
E
Königsrainer
Alfred
A
Margreiter
Raimund
R
Gnaiger
Erich
E
D000818:Animals; D001706:Biopsy; D019069:Cell Respiration / Q000502:physiology; D003080:Cold Temperature; D003574:Cytochrome c Group / Q000378:metabolism; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism*; D015427:Reperfusion Injury / Q000175:diagnosis; D013552:Swine
D003574:Cytochrome c Group