Biomaterial Database

Uptake of ornithine by rat liver mitochondria. 1981

D L Aronson, and J J Diwan

Uptake of [14C]-L-ornithine by rat liver mitochondria has been measured by using the silicone sampling technique. The uptake of ornithine measured after 20-45 s of incubation exhibits stereospecificity, pH dependence, and a lack of dependence on respiratory energy. A slower subsequent increase in [14C]-L-ornithine counts associated with the mitochondria, which is blocked by the transaminase inhibitor aminooxyacetate, is attributed to metabolism of the labeled ornithine. Each of the reagents N-ethylmaleimide, Tris (HCl) buffer, Tl2+SO42(-), Mg2+SO42(-), and choline chloride inhibits ornithine accumulation. A lack of inhibition by mersalyl is interpreted as indicating that ornithine uptake does not require transmembrane Pi flux. Uptake of ornithine to levels in excess of the concentration in the medium can largely be accounted for by an osmotically insensitive fraction of the ornithine taken up, which is assumed to be adsorbed to solid structures of the mitochondria.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
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
D009952	Ornithine	An amino acid produced in the urea cycle by the splitting off of urea from arginine.	2,5-Diaminopentanoic Acid,Ornithine Dihydrochloride, (L)-Isomer,Ornithine Hydrochloride, (D)-Isomer,Ornithine Hydrochloride, (DL)-Isomer,Ornithine Hydrochloride, (L)-Isomer,Ornithine Monoacetate, (L)-Isomer,Ornithine Monohydrobromide, (L)-Isomer,Ornithine Monohydrochloride, (D)-Isomer,Ornithine Monohydrochloride, (DL)-Isomer,Ornithine Phosphate (1:1), (L)-Isomer,Ornithine Sulfate (1:1), (L)-Isomer,Ornithine, (D)-Isomer,Ornithine, (DL)-Isomer,Ornithine, (L)-Isomer,2,5 Diaminopentanoic Acid
D005033	Ethylmaleimide	A sulfhydryl reagent that is widely used in experimental biochemical studies.	N-Ethylmaleimide,N Ethylmaleimide
D000625	Aminooxyacetic Acid	A compound that inhibits aminobutyrate aminotransferase activity in vivo, thereby raising the level of gamma-aminobutyric acid in tissues.	Aminooxyacetate,Carboxymethoxyamine,Acid, Aminooxyacetic
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
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D013237	Stereoisomerism	The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)	Molecular Stereochemistry,Stereoisomers,Stereochemistry, Molecular,Stereoisomer
D013691	Tellurium	An element that is a member of the chalcogen family. It has the atomic symbol Te, atomic number 52, and atomic weight 127.60. It has been used as a coloring agent and in the manufacture of electrical equipment. Exposure may cause nausea, vomiting, and CNS depression.