Biomaterial Database

Styrene oxide metabolism in rhesus monkey liver: enzyme activities in subcellular fractions and in isolated hepatocytes. 1983

G M Pacifici, and B Lindberg, and H Glaumann, and A Rane

The activity and the kinetic behavior of expoxide hydrolase were studied in various subcellular fractions of rhesus monkey liver isolated by differential centrifugation. The purity of the fractions was estimated by morphometric electron microscopy. Hydrolase activity was measured by a specific radiometric assay with [7-3H]styrene oxide as substrate. All isolated subcellular fractions catalyzed the hydration of styrene oxide at a significant rate. With a saturating concentration of substrate (1 mM), the enzymatic activity (nanomole of product per minute per milligram of protein; mean +/- S.E.) turned out to be 1.51 +/- 0.45 (nuclear fraction), 3.50 +/- 1.11 (mitochondrial fraction), 14.8 +/- 2.26 (microsomal fraction) and 1.69 +/- 0.37 (soluble fraction). The hydrolase obeyed Michaelis-Menten kinetics in each fraction. Vmax (nanomole per minute per milligram; mean +/- S.E.) was 1.64 +/- 0.65 (nuclear fraction) 3.87 +/- 1.71 (mitochondrial fraction), 19.8 +/- 5.4 (microsomal fraction) and 2.72 +/- 1.36 (soluble fraction). The Km (millimole; mean +/- S.E.) values in the fractions were 0.09 +/- 0.02, 0.07 +/- 0.01, 0.23 +/- 0.15 and 0.64 +/- 0.40, respectively. The metabolism of styrene oxide was also studied in isolated hepatocytes from rhesus monkey. These cells hydrated the substrate easily whereas the conjugation of styrene oxide with glutathione was not measurable. Our results show that epoxide hydrolase is present in all subcellular fractions of the rhesus monkey liver. Styrene oxide is preferentially metabolized by hydration to styrene glycol in the isolated hepatocytes of this species and no conjugation with glutathione was found under the incubation conditions used.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008253	Macaca mulatta	A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.	Chinese Rhesus Macaques,Macaca mulatta lasiota,Monkey, Rhesus,Rhesus Monkey,Rhesus Macaque,Chinese Rhesus Macaque,Macaca mulatta lasiotas,Macaque, Rhesus,Rhesus Macaque, Chinese,Rhesus Macaques,Rhesus Macaques, Chinese,Rhesus Monkeys
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
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
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D004852	Epoxy Compounds	Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.	Epoxide,Epoxides,Epoxy Compound,Oxiranes,Compound, Epoxy,Compounds, Epoxy
D004988	Ethers, Cyclic	Compounds of the general formula R-O-R arranged in a ring or crown formation.	Cyclic Ether,Cyclic Ethers,Ether, Cyclic
D005982	Glutathione Transferase	A transferase that catalyzes the addition of aliphatic, aromatic, or heterocyclic FREE RADICALS as well as EPOXIDES and arene oxides to GLUTATHIONE. Addition takes place at the SULFUR. It also catalyzes the reduction of polyol nitrate by glutathione to polyol and nitrite.	Glutathione S-Alkyltransferase,Glutathione S-Aryltransferase,Glutathione S-Epoxidetransferase,Ligandins,S-Hydroxyalkyl Glutathione Lyase,Glutathione Organic Nitrate Ester Reductase,Glutathione S-Transferase,Glutathione S-Transferase 3,Glutathione S-Transferase A,Glutathione S-Transferase B,Glutathione S-Transferase C,Glutathione S-Transferase III,Glutathione S-Transferase P,Glutathione Transferase E,Glutathione Transferase mu,Glutathione Transferases,Heme Transfer Protein,Ligandin,Yb-Glutathione-S-Transferase,Glutathione Lyase, S-Hydroxyalkyl,Glutathione S Alkyltransferase,Glutathione S Aryltransferase,Glutathione S Epoxidetransferase,Glutathione S Transferase,Glutathione S Transferase 3,Glutathione S Transferase A,Glutathione S Transferase B,Glutathione S Transferase C,Glutathione S Transferase III,Glutathione S Transferase P,Lyase, S-Hydroxyalkyl Glutathione,P, Glutathione S-Transferase,Protein, Heme Transfer,S Hydroxyalkyl Glutathione Lyase,S-Alkyltransferase, Glutathione,S-Aryltransferase, Glutathione,S-Epoxidetransferase, Glutathione,S-Transferase 3, Glutathione,S-Transferase A, Glutathione,S-Transferase B, Glutathione,S-Transferase C, Glutathione,S-Transferase III, Glutathione,S-Transferase P, Glutathione,S-Transferase, Glutathione,Transfer Protein, Heme,Transferase E, Glutathione,Transferase mu, Glutathione,Transferase, Glutathione,Transferases, Glutathione