Visualization of mitochondrial oxygen fixation in brain slices by gas-tissue autoradiography.
We have developed a novel autoradiographic method of visualizing oxygen fixation with sufficient delivery of [(15)O]O(2)/O(2). Brain slices (400 microm) were preincubated in Krebs-Ringer phosphate buffer and exposed to [(15)O]O(2) in a chamber. Fixation of [(15)O]O(2) correlated with the polarographically measured oxygen consumption among tissue slices from various organs (r=0.84). The fixation of [(15)O]O(2) by brain slices was significantly reduced (7. 2% of the control) by heat-treatment or dose dependently by NaCN (18. 2% of the control on 50 mM NaCN pretreatment). The (15)O radioactivity in the brain slices prepared from rotenone injected rats was also reduced compared to the control (56.8% of the control side). In an autoradiographic study, (15)O radioactivity showed a heterogeneous distribution both in coronal and sagittal sections. Autoradiography of young and senescent rat brain sections showed reduction of oxygen uptake with aging in the cerebrum, the senescent being 77.4% of the young. This method provides information regarding basic oxygen consumption of tissue slices under condition of sufficient O(2) delivery, which reflects mitochondrial electron transport.
Sasaki
T
T
Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Sakae-cho, Itaboshi-ku, Tokyo 173-0015, Japan. sasaki@pet.tmig.or.jp
Soga
S
S
Ishii
S
S
Kobayashi
T
T
Nagai
H
H
Senda
M
M
D000375:Aging / Q000502:physiology; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004579:Electron Transport; D004734:Energy Metabolism / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D010104:Oxygen Radioisotopes; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D012402:Rotenone / Q000494:pharmacology; D014055:Tomography, Emission-Computed
D010104:Oxygen Radioisotopes; D017382:Reactive Oxygen Species; D012402:Rotenone; D010100:Oxygen