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Mitochondrial function in sparrow pectoralis muscle
Author(s) -
Kuzmiak Sarah,
Glancy Brian,
Sweazea Karen,
Willis Wayne
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.1055.15
Subject(s) - sparrow , mitochondrion , chemistry , reactive oxygen species , mitochondrial ros , nad+ kinase , biochemistry , biology , enzyme , ecology
Birds represent an anomaly as they couple a long life span with a high metabolic rate, hyperglycemia, and insulin resistance. Despite the strong links between mitochondria (mito) and aging/longevity, no comprehensive investigation has assessed avian mitochondrial function. Mito were isolated from English sparrow pectoralis and rat mixed hindlimb muscles. Maximal O 2 consumption (Jo) and reactive oxygen species (ROS) production were measured in the presence of several oxidative substrates. NAD‐ and FAD‐linked electron transport chain (ETC) capacity was examined in sonicated mito. Compared to rat, sparrow muscle mito oxidize palmitoyl‐l‐carnitine 1.9‐fold faster (211.9 ± 25.6 vs 396.3 ± 36.4 nmol/mg/min), cannot oxidize glycerol‐3‐phosphate, and produce 60% less ROS with complex II linked substrates and both cytosolic‐mitochondrial electron shuttles. Despite similar maximal Jo for the majority of substrates, sonicated sparrow mito oxidize NADH and succinate 3‐ to 5‐fold faster than rat mito, 1809.34 ± 272.05 vs. 647.53 ± 73.07 and 416.93 ± 49.12 vs. 86.83 ± 9.23 nmol/mg/min, respectively. High ETC catalytic potential relative to matrix substrate dehydrogenases in sparrow mito suggests lower matrix redox potential necessary to drive a given O 2 consumption rate, which may contribute to the lower ROS production observed in birds compared to mammals. Research supported by a grant from the NSF (IBN‐0116997).