Phosphorylation In Rat Liver Mitochondria Research Articles

Reversible inhibition of mitochondrial respiratory control by tetrabutylammonium bromide

Influences of tetrabutylammonium bromide as a phosphorylation inhibitor and as an uncoupler of oxidative phosphorylation in rat liver mitochondria were reversed by washing the organelles. Uncoupling by 2,4-dinitrophenol was also reversible whereas gramicidin and the detergents, sodium dodecylsulfate and cetyltrimethylammonium bromide, were tightly bound uncouplers and they were not substantially removed by simple washing.

Further studies concerning the effects of 2-aryl-1,3-indandiones on oxidative phosphorylation in rat liver mitochondria

The uncoupling activities of a series of substituted 2-aryl-1,3-indandiones are highly dependent on the rate at which energy is conserved. The latter process was varied by using different substrates or by adding different amounts of amytal. The uncoupling activities determined with ascorbate as the substrate did not differ fundamentally from those obtained with glutamate and both are mainly governed by lipophilicity and electronic effects.

Effect of morphine in vitro on oxidative phosphorylation in rat liver mitochondria

The rates of respiration in the presence of ADP and of phosphorylation as an ATP-ase activity of rat liver mitochondria was inhibited was in vitro by morphine with Ki=6.5 mM. The uncoupler-stimulated respiration of the mitochondria and the activity of ATP-ase and synthesis of ATP in the submitochondrial particles were not altered in the presence of morphine. It is suggested that morphine inhibited the adenine nucleotide transport through the mitochondrial membrane

Effect of albumin on uncoupling of oxidative phosphorylation by chinoform in rat liver mitochondria.

Addition of serum albumin diminished the uncoupling effect of chinoform on oxidative phosphorylation in rat liver mitochondria. Upon increasing the concentration of magnesium ions in the medium, the action of serum albumin was diminished. These results indicate that serum albumin combines with chinoform in competition with magnesium ions.

The action of cyclodiene pesticides on oxidative phosphorylation in rat liver mitochondria

The effects of a number of chlorinated hydrocarbon pesticides have been studied on isolated rat liver mitochondria. Inhibition of mitochondrial function was found to be dependent upon the ratio of pesticide to protein, and to some extent upon the type of pesticide. Most of the pesticides tested exerted more than one effect depending upon the concentration. At low concentrations (less than 20–25 nmoles/mg protein). State 3 respiration, DNP-activated respiration and valinomycin-induced swelling were inhibited by certain cyclodienes. These results cannot be explained by inhibition of the electron transport chain or uncoupling. They appear to be associated with restrictions of ion movements across the membrane (DNP, valinomycin-K + complex, ADP). On increasing the concentration of pesticide, lysis of the membranes and uncoupling can be induced. The electron transport chain can also be inhibited, but only with 5–10 times greater concentrations of pesticide than required for uncoupling. In general, the cyclodiene pesticides are slightly more effective inhibitors than the non-cyclodienes tested.† The effectiveness of the cyclodienes is, however, dependent upon its stereochemical properties. These findings suggest that the cyclodienes may inhibit mitochondria in a common, and, perhaps, specific manner. The specificity and mode of action of cyclodienes was found to be similar to that described earlier (B.D. Nelson and C. Williams, Agric. fd Chem. 19, 339 (1971)), using growing yeast cells as the test system.

Effects of anti-inflammatory 2-aryl-1,3-indandiones on oxidative phosphorylation in rat liver mitochondria

A number of 2-aryl-1,3-indandiones were examined for action on oxidative phosphorylation in rat liver mitochondria. They were all found to be uncouplers and to stimulate state 4 respiration and mitochondrial ATPase and to reduce the P/O ratio. There exists a marked difference in activity between 2-aryl-1,3-indandiones with and without ortho substituents. The latter have the same properties as 2,4-dinitrophenol. Uncoupling activity is dependent on the presence of an acid proton but lipophilicity also plays a major role. In high concentrations, all 2-aryl-1,3-indandiones can inhibit respiration but with the ortho-substituted compounds inhibition is most overt. The anti-inflammatory activities of 2-aryl-1,3-indandiones, as determined in a carrageenan oedema test, showed no relationship to uncoupling of oxidative phosphorylation.

Further studies concerning the effects of clofibrate on respiration and oxidative phosphorylation of rat liver mitochondria

Clofibrate, administered in vitro, inhibited rat liver mitochondrial respiration at two sites within the respiratory chain. One site was between the interaction of NADH with NADH dehydrogenase and the point at which electrons from succinate oxidation enter the electron transport chain; another, less sensitive site, was between the interaction of succinate with succinate dehydrogenase and cytochrome c. In addition to these specific sites, clofibrate inhibited respiration by causing a depletion of pyridine nucleotides that was accompanied or followed by large-amplitude, non-energy-linked swelling. Clofibrate uncoupled oxidative phosphorylation at coupling sites II and III but not at site I. The concentrations required to cause loss of pyridine nucleotides were lower than those required to inhibit at the specific sites. p-Chlorophenoxyisobutyrate (CPIB) also inhibited succinate and β-hydroxybutyrate-linked respiration, and uncoupled oxidative phosphorylation, but at much higher concentrations (50 per cent inhibition of β-hydroxybutyrate oxidation at about 3·7 μmoles/mg of protein) than were required of clofibrate (50 per cent inhibition of β-hydroxybutyrate oxidation at about 0·17 μmole/mg of protein). Clofibrate administration to rats (100 and 300 mg/kg p.o. daily for 1 week) lowered serum lipid levels and increased the liver size, the amount of mitochondrial protein/g of liver, and the oxygen consumption of liver slices. However, mitochondria, isolated from livers of the treated rats, respired normally. A single administration of clofibrate (100 or 300 mg/kg, p.o.) did not affect liver slice respiration.

Effects of SC-26096 [2-methyl-3-oxo-2-azabicyclo (2.2.2.) octan-6- exo-yl 5-(4-biphenylyl)-3-methyl valerate], a new hypolipidemic agent, on mitochondrial respiration and oxidative phosphorylation

The effects of SC-26096 [2-methyl-3-oxo-2-azabicyclo (2.2.2.) octan-6- exo-yl 5-(4-biphenylyl)-3-methyl valerate] on respiration and oxidative phosphorylation of rat liver mitochondria were studied in vitro. It was found that SC-26096 is an inhibitor of electron transport. In preparations of intact and sonicated mitochondria, the drug effectively inhibited NAD-linked respiration at low concentration and inhibited succinate-linked respiration at much higher concentration. In intact mitochondria, dinitrophenol partially reversed the inhibition of NAD-linked state 3 repiration but did not reverse the inhibition of succinate-linked respiration. At the SC-26096 concentrations which were required to inhibit succinate oxidation. ADP:O ratio of phosphorylation site III was lowered and state 4 oxidation rate and ATPase activities were raised. At the drug concentrations which were tested. SC-26096 did not alter the ADP:O ratio of phosphorylation site II. 3-Hydroxybutyrate oxidation by mitochondria which were pretreated with SC-26096 remained inhibited after washing with 0.25 M sucrose, but this inhibition was relieved by adding albumin. The effects of SC-26096 were primarily dependent upon the ratio of drug:mitochondrial protein and not upon the initial molarity of the drug in the incubation medium. The results suggest that SC-26096 is bound to mitochondria in vitro and that the bound drug produces the mitochondrial effects. At least two sites of inhibition, within the respiratory chain, are indicated. One site lies between the interaction of NADH with NADH dehydrogenase and the point at which electrons from succinate oxidation enter the electron transport system. A second, less sensitive, site lies between the interaction of succinate with succinate dehydrogenase and cytochrome c. A third inhibitory site appears to be present in the site I phosphorylation system at or distal to the dinitrophenol-sensitive site.

Spegazzinine, a new inhibitor of mitochondrial oxidative phosphorylation

The effects of spegazzinine, a dihydroindole alkaloid, on mitochondrial oxidative phosphorylation were studied. Spegazzinine inhibited coupled respiration and phosphorylation in rat liver mitochondria. The I 50 was 120 μM. Uncouplers released the inhibition of coupled respiration. Arsenate-stimulated mitochondrial respiration was partially inhibited by spegazzinine. The stimulation of mitochondrial respiration by Ca 2+ and the proton ejection associated with the ATP-dependent Ca 2+ uptake were not affected by the alkaloid. Oxidative phosphorylation and the P i-ATP exchange reaction of phosphorylating beef heart submitochondrial particles were strongly inhibited by spegazzinine ( I 50, 50 μM) while the ATP-dependent reactions, reduction of NAD + by succinate and the pyridine nucleotides transhydrogenase were less sensitive ( I 50, 125 μM). Oxygen uptake by submitochondrial particles was not affected. The 2,4-dinitrophenol-stimulated ATPase activity of rat liver mitochondria was not affected by 300 μM spegazzinine, a concentration of alkaloid that completely inhibited phosphorylation. However, higher concentrations of spegazzinine did partially inhibit it. The ATPase activities of submitochondrial particles, insoluble and soluble ATPases were also partially inhibited by high concentrations of spegazzinine. The inhibitory properties of spegazzinine on energy transfer reactions are compared with those of oligomycin, aurovertin and dicyclohexylcarbodiimide. It is concluded that spegazzinine effects are very similar to the effects of aurovertin and that its site of action may be the same or near the site of aurovertin.

Chlordimeform: Uncoupling activity against rat liver mitochondria

The pesticide chlordimeform [ N′-(4-chloro- o-tolyl)- N,N-dimethylformamidine] at 0.04 μmoles/mg protein uncouples 50% of respiratory-chain phosphorylation of rat liver mitochondria. This uncoupling activity depends on mitochondrial protein concentration and can be reversed either by the addition of bovine serum albumin or by washing. The normal inhibition of state 3 respiration by oligomycin and atractylate is completely reversed by chlordimeform. Uncoupling concentrations of chlordimeform elicit high adenosine triphosphatase activity. This activity is blocked by the above inhibitors of mitochondrial energy-transfer reactions. Evidence is presented which shows that unprotonated chlordimeform is the form effective in uncoupling. It is concluded that chlordimeform is an uncoupling agent with a potency and site of action close to but probably not identical to that of the classical uncoupler 2,4-dinitrophenol.

The effect of crustacean black pigment dispersing hormone on oxidative phosphorylation in rat liver mitochondria

1. 1. Black Pigment Dispersing Hormone (BPDH) inhibits oxidation of succinate by intact rat liver mitochondria. This inhibition was overcome by the classical uncoupling agents, calcium ion, NH 4Cl+gramicidin, but not by gramicidin+K +. 2. 2. The inhibition of succinate oxidation by BPDH in intact rat liver mitochondria in metabolic state 3 was also reversed by some anions. 3. 3. BPDH was without effect on succinate oxidation in sonic particles. 4. 4. BPDH inhibited ATP synthesis with succinate as substrate. 5. 5. BPDH was without effect on ATP-ase activity stimulated by 2,4-dinitrophenol. 6. 6. The experiments described suggest that BPDH inhibits oxidative phosphorylation.

Uncoupling of Oxidative Phosphorylation of Rat Liver Mitochondria by Chinoform

Uncoupling of Oxidative Phosphorylation of Rat Liver Mitochondria by Chinoform

Synthesis of spin labelled 2,4-dinitrophenols and their activities in the uncoupling of oxidative phosphorylation in rat liver mitochondria

Two spin labelled dinitrophenols [1-Hydroxyl-5-N-(1-oxyl-2,2,5,5-tetramethyl-3-amino-pyrrolidinyl)-2,4-dinitrobenzene, and 1-Hydroxyl-5-N-(1-oxyl-2,2,5,5-tetramethyl-3-amino-methylpyrrolidinyl)-2,4-dinitrobenzene] were prepared and found to retain full activity in the uncoupling of oxidative phosphorylation in rat liver mitochondria. Spin labelled 2,4-dinitrobenzene analogues are inactive.

PH effects on oxidative phosphorylation of rat liver mitochondria.

ARTICLESpH effects on oxidative phosphorylation of rat liver mitochondriaRB Tobin, CR Mackerer, and MA MehlmanRB Tobin, CR Mackerer, and MA MehlmanPublished Online:01 Jul 1972https://doi.org/10.1152/ajplegacy.1972.223.1.83MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByMagnetic Resonance-Compatible Arm-Crank Ergometry: A New Platform Linking Whole-Body Calorimetry to Upper-Extremity Biomechanics and Arm Muscle Metabolism19 February 2021 | Frontiers in Physiology, Vol. 12Combined in vivo and in silico investigations of activation of glycolysis in contracting skeletal muscleJ. P. J. Schmitz*, W. Groenendaal*, B. Wessels, R. W. Wiseman, P. A. J. Hilbers, K. Nicolay, J. J. Prompers, J. A. L. Jeneson, and N. A. W. van Riel15 January 2013 | American Journal of Physiology-Cell Physiology, Vol. 304, No. 2Unchanged muscle fiber conduction velocity relates to mild acidosis during exhaustive bicycling23 August 2011 | European Journal of Applied Physiology, Vol. 112, No. 5Silencing of glycolysis in muscle: experimental observation and numerical analysis8 January 2010 | Experimental Physiology, Vol. 95, No. 2Intersubject differences in the effect of acidosis on phosphocreatine recovery kinetics in muscle after exercise are due to differences in proton efflux ratesNicole M. A. van den Broek, Henk M. M. L. De Feyter, Larry de Graaf, Klaas Nicolay, and Jeanine J. Prompers1 July 2007 | American Journal of Physiology-Cell Physiology, Vol. 293, No. 1The Effects of Ecstasy (MDMA) on Rat Liver BioenergeticsAcademic Emergency Medicine, Vol. 11, No. 7Actively phosphorylating mitochondria are more resistant to lactic acidosis than inactive mitochondriaM. Tonkonogi, and K. Sahlin1 August 1999 | American Journal of Physiology-Cell Physiology, Vol. 277, No. 2Impaired hepatic mitochondrial function reserve in brain-dead pigsTransplantation Proceedings, Vol. 30, No. 8Metabolic and energetic properties of isolated nerve ending particles (synaptosomes)Biochimica et Biophysica Acta (BBA) - Bioenergetics, Vol. 1277, No. 1-2Oxidative phosphorylation and the realkalinization of intracellular pH during recovery from anoxia in Artemia franciscana embryosBiochimica et Biophysica Acta (BBA) - Bioenergetics, Vol. 1232, No. 1-2Relations Between Intracellular Ions and Energy Metabolism Under Acidotic Conditions: A Study with Nigericin in Synaptosomes, Neurons, and C6 Glioma CellsJournal of Neurochemistry, Vol. 61, No. 4Brain cellular and mitochondrial respiration in media of altered pHMetabolic Brain Disease, Vol. 2, No. 2Free radical theory of aging: Effects of antioxidants on mitochondrial functionAGE, Vol. 10, No. 2In Vivo Recruitment of Mitochondrial $$% MathType!MTEF!2!1!+- % feaagCart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaaeaaaaaaaaa8 % qaceWGwbGbaiaacaWGpbWaaSbaaSqaaiaaikdaaeqaaaaa!38B4! $$\dot V{O_2}$$$$ : Test of Current Models Using Tissue DataThyroxine-induced changes in rat liver mitochondrial ubiquinoneBiochemical and Biophysical Research Communications, Vol. 138, No. 1Thyroxine-induced changes in rat liver mitochondrial cytochromesMolecular and Cellular Endocrinology, Vol. 41, No. 2-3Influence of in vitro Lactic Acidosis and Hypercapnia on Respiratory Activity of Isolated Rat Brain Mitochondria29 June 2016 | Journal of Cerebral Blood Flow & Metabolism, Vol. 4, No. 3The effects of hydrogen ions on the kinetics of calcium transport by rat kidney mitochondriaArchives of Biochemistry and Biophysics, Vol. 203, No. 2A minimal toxicity approach to cancer therapy: Possible role of beta-glucuronidaseMedical Hypotheses, Vol. 6, No. 1Steady state kinetics of energy-dependent Ca2+ uptake in rat liver mitochondria.Journal of Biological Chemistry, Vol. 252, No. 13Intracellular PH: Measurement, Control, and Metabolic Interrelationships27 September 2008 | CRC Critical Reviews in Clinical Laboratory Sciences, Vol. 6, No. 2Effects of chronic acetylsalicylate administration on several nutritional and biochemical parameters in rats fed diets of varied thiamin contentBiochemical Medicine, Vol. 8, No. 1 More from this issue > Volume 223Issue 1July 1972Pages 83-88 Copyright & PermissionsCopyright © 1972 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1972.223.1.83PubMed5039078History Published online 1 July 1972 Published in print 1 July 1972 Metrics

Desdanine, an inhibitor of oxidative phosphorylation in mitochondria.

The antibiotic, desdanine, acts as an uncoupling agent of oxidative phosphorylation in rat liver mitochondria. In addition, mitochondrial respiration is also impaired but to a lesser degree. Studies of individual reaction sequences occurring within the respiratory chain indicate that desdanine interferes with electron transfer at the flavoprotein regions associated with the oxidation of NADH and succinate. The flavoprotein region associated with the oxidation of succinate is more susceptible to desdanine than the NADH-linked flavoprotein region.

Effects in vitro and in vivo of methylenedioxy-phenyl compounds on oxidative phosphorylation in rat liver mitochondria

The methylenedioxyphenyl compounds, piperonyl butoxide (P.B.), tropital, myristicin and piperonal were tested for their action in vitro on oxidative phosphorylation using rat liver mitochondria. These compounds inhibited state 3 respiration and uncoupled oxidative phosphorylation in the decreasing order: piperonyl butoxide, tropital and myristicin. Piperonal had little, if any, effect on mitochondrial function indicating that the side-chain, not the methylenedioxyphenyl moiety, conferred uncoupling activity. The I 50 of P.B. on state 3 respiration was approximately 50 mμmoles per mg protein with glutamate and β-hydroxybutyrate, and 100 mμmoles/mg with succinate as the substrate. The I 50 of P.B. on NADH-oxidase and succinoxidase of electron transport particles was 500 and 2500 mμmoles per mg protein, respectively, indicating a lesser effect on the respiratory chain than on phosphorylation. Studies were also conducted to determine if P.B. selectively inhibited mitochondrial function in vivo. Up to 880 mg P.B./kg failed to inhibit either mitochondrial function, or aniline hydroxylase and aminopyrine demethylase activities in mitochondria and microsomes isolated from treated rats and assayed in vitro. Similar results were obtained using rats pretreated with phenobarbital for 3 days. The significance of these findings relative to the in vivo site of P.B. action is discussed.

The effect of 2-phenylisatogen on oxidative phosphorylation in rat liver mitochondria

The effect of 2-phenylisatogen on oxidative phosphorylation in rat liver mitochondria

Effect of 2, 4-dinitrophenol (DNP) on oxidative phosphorylation in rat liver mitochondria

The effects of a range of DNP concentrations on ADP/O ratio, respiratory control index (RCI), and stimulation of latent ATPase activity of mitochondria have been studied using various substrates. The first and third sites of phosphorylation were found to be more sensitive to DNP action as compared to the second site. No correlation could be seen between any of the three parameters studied. Fluoride was inhibitory to the stimulation of ATPase by DNP only in presence of high concentrations of DNP, but had no inhibitory effect at low DNP concentrations. The inhibitory effects of fluoride and substrates were not additive.

2-Anilinothiophene als Entkoppler der oxydativen Phosphorylierung in Mitochondrien / 2-Anilinothiophenes, Uncouplers of Oxidative Phosphorylation in Mitochondria

A series of NH-acidic 2-anilino-3,5-dinitro-thiophenes (II), 2-anilino-3,4-dinitro-5-halo-thiophenes (VI), and some 3,5-dinitro-thienole-derivatives (IX, X) were synthesized. Compounds II and VI are potent uncouplers of oxidative phosphorylation in rat liver mitochondria. The most active comcounds yielded a 50% uncoupling at a concentration of 10-7 ᴍ. With some of the 2-anilino-3,5-dinitro-5-halo-thiophenes (BDCT or DDCT), added to respiring liver mitochondria, a transitory uncoupling of energy-linked reactions could be observed which is comparable to the phosphorylating cycles produced by ADP. The mechanism of this effect is discussed

On the Role of K+ on Oxidative Phosphorylation

Abstract The influence of K+ on oxidative phosphorylation of rat liver mitochondria has been investigated. Fresh mitochondria undergo a loss of respiratory control concomitantly with the loss of K+, and a rough correlation was found between the K+ content of the mitochondria and the State 3 to State 4 respiratory ratio. K+-depleted mitochondria have a low respiratory control with NAD-dependent substrates which is significantly enhanced by adding K+ during State 4; K+, added during State 3, fails to affect respiration. Apparently, the respiratory response of the mitochondria to the cation is regulated by its metabolic state. The favorable effect of K+ on oxidative phosphorylation is independent of its action in promoting the entrance of oxidizable substrates into the mitochondria. In K+-depleted mitochondria, there are certain conditions in which valinomycin, but not 2,4-dinitrophenol, stimulates the respiratory activity. As evidenced by swelling experiments, valinomycin induces the passive entrance of K+ into the K+-depleted mitochondria. The results of an attempt to determine the distribution of K+ in the population of mitochondria which have been depleted of K+ suggest that a significant part of the population has extremely low levels of K+, whereas a small part has an adequate concentration of K+. The favorable effect of K+ on mitochondrial respiration is not specific, and other cations, except Na+, may substitute for K+. The order of effectiveness of the cations in inducing respiratory control in K+-depleted mitochondria follows the order by which cations alter the structure of macromolecules.