Biomaterial Database

Is monoamine oxidase activity in the outer mitochondrial membrane influenced by the mitochondrial respiratory state? 1995

A B Wojtczak, and D Brdiczka, and L Wojtczak

Nencki Institute of Experimental Biology, Warsaw, Poland.

Monoamine oxidase activity was measured in isolated rat liver mitochondria using the radiochemical assay with [14C]tyramine as substrate. With toluene as the extracting solvent the apparent activity in the resting state (State 4) was much higher than in the active state (State 3) in agreement with Smith and Reid (Smith, G.S. and Reid, R.A. (1978) Biochem. J. 176, 1011-1014). However, with ethyl acetate or diethyl ether as extracting solvents, the activity in both states was almost identical and several times higher than that measured with toluene. p-Hydroxyphenylacetaldehyde, p-hydroxyphenylacetalcohol and p-hydroxyphenylacetic acid were identified as final reaction products, the latter one being hardly extractable with toluene. It is concluded that monoamine oxidase activity is not influenced by the respiratory state of mitochondria and that differences found by Smith and Reid are due to different extractability of secondary reaction products. NADPH-dependent aldehyde reductase was tentatively identified in rat liver mitochondria, its specific activity amounting to about one fourth of that in the cytosol.

UI	MeSH Term	Description	Entries
D007425	Intracellular Membranes	Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.	Membranes, Intracellular,Intracellular Membrane,Membrane, Intracellular
D008297	Male		Males
D008930	Mitochondria, Liver	Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)	Liver Mitochondria,Liver Mitochondrion,Mitochondrion, Liver
D008995	Monoamine Oxidase	An enzyme that catalyzes the oxidative deamination of naturally occurring monoamines. It is a flavin-containing enzyme that is localized in mitochondrial membranes, whether in nerve terminals, the liver, or other organs. Monoamine oxidase is important in regulating the metabolic degradation of catecholamines and serotonin in neural or target tissues. Hepatic monoamine oxidase has a crucial defensive role in inactivating circulating monoamines or those, such as tyramine, that originate in the gut and are absorbed into the portal circulation. (From Goodman and Gilman's, The Pharmacological Basis of Therapeutics, 8th ed, p415) EC 1.4.3.4.	Amine Oxidase (Flavin-Containing),MAO,MAO-A,MAO-B,Monoamine Oxidase A,Monoamine Oxidase B,Type A Monoamine Oxidase,Type B Monoamine Oxidase,Tyramine Oxidase,MAO A,MAO B,Oxidase, Monoamine,Oxidase, Tyramine
D009249	NADP	Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)	Coenzyme II,Nicotinamide-Adenine Dinucleotide Phosphate,Triphosphopyridine Nucleotide,NADPH,Dinucleotide Phosphate, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide Phosphate,Nucleotide, Triphosphopyridine,Phosphate, Nicotinamide-Adenine Dinucleotide
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D000449	Aldehyde Reductase	An enzyme that catalyzes reversibly the oxidation of an aldose to an alditol. It possesses broad specificity for many aldoses. EC 1.1.1.21.	Aldose Reductase,Aldose Reductase Ia,Aldose Reductase Ib,Erythrose Reductase,Xylose Reductase,Reductase Ia, Aldose,Reductase Ib, Aldose,Reductase, Aldehyde,Reductase, Aldose,Reductase, Erythrose,Reductase, Xylose
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012997	Solvents	Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)	Solvent
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats