Biomaterial Database

Effects of sesquiterpene lactones on mitochondrial oxidative phosphorylation. 1989

T R Narasimham, and H L Kim, and S H Safe

Department of Veterinary Physiology and Pharmacology Texas A & M University, College Station 77843.

1. The toxic plant sesquiterpene lactones, helenalin, hymenoxon, mexicanin-E, tenulin, dihydrogriesenin, and psilotropin which were isolated from Helenium, Hymenoxys, and Geigeria spp markedly inhibited "state 3" respiration in mouse hepatic mitochondria. With the exception of dihydrogriesenin and psilotropin, all the other sesquiterpene lactones stimulated "state 4" respiration. 2. The sesquiterpene lactones also stimulated ATPase activity in the presence of Mg2+ ions and caused mitochondrial swelling in buffer solutions containing magnesium, sodium, ammonium and potassium chloride salts. 3. The number of alkylating sites present in a sesquiterpene lactone appears to be related to the inhibitory activity on mitochondrial oxidative phosphorylation, however, the structure-activity relationship of these lactones is not clear at present. 4. Mitochondria prepared from the liver of ethoxyquin hydrochloride-fed mice were less susceptible to sesquiterpene lactone-mediated inhibition of mitochondrial oxidative phosphorylation.

UI	MeSH Term	Description	Entries
D007783	Lactones	Cyclic esters of hydroxy carboxylic acids, containing a 1-oxacycloalkan-2-one structure. Large cyclic lactones of over a dozen atoms are MACROLIDES.	Lactone
D008813	Mice, Inbred ICR	An inbred strain of mouse that is used as a general purpose research strain, for therapeutic drug testing, and for the genetic analysis of CARCINOGEN-induced COLON CANCER.	Mice, Inbred ICRC,Mice, ICR,Mouse, ICR,Mouse, Inbred ICR,Mouse, Inbred ICRC,ICR Mice,ICR Mice, Inbred,ICR Mouse,ICR Mouse, Inbred,ICRC Mice, Inbred,ICRC Mouse, Inbred,Inbred ICR Mice,Inbred ICR Mouse,Inbred ICRC Mice,Inbred ICRC Mouse
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
D008933	Mitochondrial Swelling	An increase in MITOCHONDRIAL VOLUME due to an influx of fluid; it occurs in hypotonic solutions due to osmotic pressure and in isotonic solutions as a result of altered permeability of the membranes of respiring mitochondria.	Giant Mitochondria,Megamitochondria,Mitochondrial Hypertrophy,Giant Mitochondrias,Hypertrophy, Mitochondrial,Megamitochondrias,Mitochondria, Giant,Mitochondrial Hypertrophies,Swelling, Mitochondrial
D009840	Oligomycins	A closely related group of toxic substances elaborated by various strains of Streptomyces. They are 26-membered macrolides with lactone moieties and double bonds and inhibit various ATPases, causing uncoupling of phosphorylation from mitochondrial respiration. Used as tools in cytochemistry. Some specific oligomycins are RUTAMYCIN, peliomycin, and botrycidin (formerly venturicidin X).	Oligomycin
D010085	Oxidative Phosphorylation	Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.	Phosphorylation, Oxidative,Oxidative Phosphorylations,Phosphorylations, Oxidative
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D005260	Female		Females
D000251	Adenosine Triphosphatases	A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.	ATPases,Adenosinetriphosphatase,ATPase,ATPase, DNA-Dependent,Adenosine Triphosphatase,DNA-Dependent ATPase,DNA-Dependent Adenosinetriphosphatases,ATPase, DNA Dependent,Adenosinetriphosphatases, DNA-Dependent,DNA Dependent ATPase,DNA Dependent Adenosinetriphosphatases,Triphosphatase, Adenosine