Biomaterial Database

Optical characterization of heme a + a3 and copper of cytochrome oxidase in blood-free perfused rat brain. 1998

Y Nomura, and A Matsunaga, and M Tamura

Biophysics Division, Hokkaido University, Sapporo, Japan. ynomura@imdes.hokudai.ac.jp

For the precise examination of the optical characteristics of cerebral tissue, we prepared hemoglobin-free perfused rat heads, from which trace amounts of blood were completely removed. In this preparation at 30 degrees C, the redox responses of the cytochrome oxidase components, heme a + a3 and copper, were followed spectrophotometrically in visible and near-infrared regions, and were correlated with the changes in neural activity as monitored by electroencephalography (EEG). During the aerobic-anaerobic transition, there was clear dissociation of the time courses of the reduction of heme a + a3 and copper; the reduction of heme a + a3 preceded the reduction of copper. The EEG activity decreased earlier than the reduction of heme a + a3. Pentylenetetrazole administration in normoxia caused the partial reduction of heme a + a3 but not of copper. The redox behaviors of cytochrome oxidase components in the brain were identical to those observed in isolated mitochondria. The usefulness of brain preparation for bridging the in vivo and in vitro studies is documented where various circulatory parameters could be controlled artificially.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002534	Hypoxia, Brain	A reduction in brain oxygen supply due to ANOXEMIA (a reduced amount of oxygen being carried in the blood by HEMOGLOBIN), or to a restriction of the blood supply to the brain, or both. Severe hypoxia is referred to as anoxia and is a relatively common cause of injury to the central nervous system. Prolonged brain anoxia may lead to BRAIN DEATH or a PERSISTENT VEGETATIVE STATE. Histologically, this condition is characterized by neuronal loss which is most prominent in the HIPPOCAMPUS; GLOBUS PALLIDUS; CEREBELLUM; and inferior olives.	Anoxia, Brain,Anoxic Encephalopathy,Brain Hypoxia,Cerebral Anoxia,Encephalopathy, Hypoxic,Hypoxic Encephalopathy,Anoxia, Cerebral,Anoxic Brain Damage,Brain Anoxia,Cerebral Hypoxia,Hypoxia, Cerebral,Hypoxic Brain Damage,Anoxic Encephalopathies,Brain Damage, Anoxic,Brain Damage, Hypoxic,Damage, Anoxic Brain,Damage, Hypoxic Brain,Encephalopathies, Anoxic,Encephalopathies, Hypoxic,Encephalopathy, Anoxic,Hypoxic Encephalopathies
D003292	Convulsants	Substances that act in the brain stem or spinal cord to produce tonic or clonic convulsions, often by removing normal inhibitory tone. They were formerly used to stimulate respiration or as antidotes to barbiturate overdose. They are now most commonly used as experimental tools.	Convulsant,Convulsant Effect,Convulsant Effects,Effect, Convulsant,Effects, Convulsant
D003300	Copper	A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.	Copper-63,Copper 63
D003576	Electron Transport Complex IV	A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.	Cytochrome Oxidase,Cytochrome aa3,Cytochrome-c Oxidase,Cytochrome Oxidase Subunit III,Cytochrome a,a3,Cytochrome c Oxidase Subunit VIa,Cytochrome-c Oxidase (Complex IV),Cytochrome-c Oxidase Subunit III,Cytochrome-c Oxidase Subunit IV,Ferrocytochrome c Oxygen Oxidoreductase,Heme aa3 Cytochrome Oxidase,Pre-CTOX p25,Signal Peptide p25-Subunit IV Cytochrome Oxidase,Subunit III, Cytochrome Oxidase,p25 Presequence Peptide-Cytochrome Oxidase,Cytochrome c Oxidase,Cytochrome c Oxidase Subunit III,Cytochrome c Oxidase Subunit IV,Oxidase, Cytochrome,Oxidase, Cytochrome-c,Signal Peptide p25 Subunit IV Cytochrome Oxidase,p25 Presequence Peptide Cytochrome Oxidase
D004569	Electroencephalography	Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.	EEG,Electroencephalogram,Electroencephalograms
D006418	Heme	The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.	Ferroprotoporphyrin,Protoheme,Haem,Heme b,Protoheme IX