THE RESPIRATORY DEPENDENT SWELLING OF LIVER MITOCHONDRIA

1966 ◽  
Vol 44 (9) ◽  
pp. 1259-1270
Author(s):  
Roberto Cereijo-Santaló
Keyword(s):  
Reduced Glutathione ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Endogenous Respiration ◽  
Mitochondrial Membranes ◽  
Ph Values ◽  
Sucrose Medium ◽  
Lag Period ◽  
Ph Range ◽  
Reduced Nicotinamide Adenine Dinucleotide

The respiratory dependent swelling of isolated rat liver mitochondria was studied in sucrose and in potassium chloride media.In a sucrose medium it was found that mitochondria did not swell in the absence of respiration over the pH range 7.0–8.0. However, swelling of mitochondria readily occurred during the oxidation of endogenous or added respiratory substrates. Maximum rates of swelling at pH 7.0 were observed with ascorbate, reduced glutathione, and reduced nicotinamide–adenine dinucleotide (NADH). The swelling induced by substrate oxidation in a sucrose medium was markedly inhibited by the addition of KCl.In a KCl medium, mitochondria swelled in the absence of respiration at acid (6.0) and at alkaline (8.0) pH values, but were stable at pH 7.0–7.4. Endogenous respiration did not modify these results. The addition of β-hydroxybutyrate induced maximum swelling at pH 7.0. The extent of swelling produced by this substrate diminished when either the pH or the molarity of the buffer was increased. Ascorbate and reduced glutathione failed to induce swelling in a KCl medium. NADH in a KCl medium produced swelling to about the same extent as that in a sucrose medium. However, the onset of the swelling was delayed in the KCl medium. This lag period was shortened by the addition of rotenone and it was lengthened when either the molarity or the pH of the buffer was increased.An attempt has been made to relate these results to proton pressure produced in the mitochondrial membranes during electron transport.

scholarly journals Studies on the efflux of metalloporphyrin from rat liver mitochondria. Effect of K+ and other cations

1981 ◽  
Vol 196 (2) ◽  
pp. 451-457 ◽  
Author(s):  
P Husby ◽  
I Romslo
Keyword(s):  
Ionic Strength ◽  
Rat Liver ◽  
Incubation Medium ◽  
Energy State ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Isolated Rat Liver ◽  
Sucrose Medium ◽  
Low Ionic Strength ◽  
Isolated Rat

The mechanism by which metalloporphyrins synthesized within the mitochondria escape to the incubation medium was studied in isolated rat liver mitochondria. In a low-ionic-strength sucrose medium, the efflux of metalloporphyrins is markedly decreased when K+ (greater than 10 mM) is added. The effect of K+ is not dependent on the energy state of the mitochondria and it can in part be abolished by adding globin, but not albumin. K+ also decreases the uptake of porphyrins by the mitochondria and thereby the rate of synthesis of metalloporphyrins. Qualitatively similar results are found with Na+, Li+, Mg2+ and Ca2+. Quantitatively, however, the efficiency of cations to inhibit the release of metalloporphyrins decreases in the order: Mg2+ greater than Ca2+ greater than K+ greater than Li+ greater than Na+. Co-protoporhyrin behaves essentially as Co-deuteroporphyrin. The results provide further evidence that the efflux of metalloporphyrins from the mitochondria depends on haem-binding ligands of the suspending medium and also on the ionic strength of the incubation medium.

scholarly journals Transport of reduced nicotinamide–adenine dinucleotide into mitochondria of rat white adipose tissue

1970 ◽  
Vol 116 (2) ◽  
pp. 229-233 ◽  
Author(s):  
B. H. Robinson ◽  
M. L. Halperin
Keyword(s):  
Adipose Tissue ◽  
Rat Liver ◽  
White Adipose Tissue ◽  
Nicotinamide Adenine Dinucleotide ◽  
Aspartate Aminotransferase ◽  
Respiratory Control ◽  
Liver Mitochondria ◽  
Nadh Oxidation ◽  
Rat Liver Mitochondria ◽  
Reduced Nicotinamide Adenine Dinucleotide

Mitochondria from rat white adipose tissue were prepared, exhibiting good respiratory control and P/O ratios. They would not oxidize NADH unless NNN′N′-tetramethyl-p-phenylenediamine was added as a carrier of reducing equivalents. These mitochondria were found to oxidize neither l-glycerol 3-phosphate nor l-glutamate plus l-malate at significant rates. The activity of aspartate aminotransferase in these mitochondria was found to be low compared with that found in rat liver mitochondria. As a consequence of this, the adipose-tissue mitochondria exhibited very low rates of cytoplasmic NADH oxidation in a reconstituted Borst (1962) cycle compared with liver mitochondria.

MITOCHONDRIAL SWELLING AT ACID pH

1966 ◽  
Vol 44 (6) ◽  
pp. 695-706 ◽  
Author(s):  
Roberto Cereijq-Santaló
Keyword(s):  
Hydrochloric Acid ◽  
Maximum Rate ◽  
Liver Mitochondria ◽  
Inhibitory Effect ◽  
Buffering Capacity ◽  
Rat Liver Mitochondria ◽  
Isotonic Solution ◽  
Ph Values ◽  
Acid Ph ◽  
Protein Gel

The effect of variations of pH on swelling of rat liver mitochondria was studied.It was found that mitochondria swell at acid pH (5.0–6.0) when they are incubated in isotonic solution of potassium chloride. The extent of swelling increased with decreasing tonicity of the medium. However, mitochondria did not swell at acid pH when they were incubated in isotonic sucrose. The inhibitory effect of sucrose was partially released by the addition of electrolytes to the medium.When unbuffered suspensions of mitochondria with different pH values were prepared by the addition of hydrochloric acid or sodium hydroxide to the incubation medium, it was observed that the extent of swelling increased both with acidity (6.0 to 5.0) and with alkalinity (7.0 to 8.0).Titration of the unbuffered mitochondrial suspensions showed a maximum buffering capacity in the ranges of pH values where maximum rate of swelling occurred.These results suggest that the mitochondrion behaves as a combination of osmometer and protein gel.

scholarly journals ROLE OF EDTA AND METALS IN MITOCHONDRIAL CONTRACTION

1964 ◽  
Vol 23 (1) ◽  
pp. 9-19 ◽  
Author(s):  
William S. Lynn ◽  
Sydney Fortney ◽  
Rose H. Brown
Keyword(s):  
Atp Hydrolysis ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Mitochondrial Matrix ◽  
Mitochondrial Membranes ◽  
Semipermeable Membranes ◽  
Microscopic Appearance ◽  
Hydration And Dehydration ◽  
Mitochondrial Contraction

Studies comparing the state of hydration and dehydration of rat liver mitochondria to their content of ATP, Ca, and fatty acid, along with the rate of ATP hydrolysis, as well as microscopic appearance of mitochondria, have led to the following generalizations: 1. The competition between cationic translocations and water translocation for the available chemical energy (ATP) determines under many circumstances the water content of mitochondria. 2. Swelling of mitochondria by electron transport substrates is an example of the activation of the cationic translocations at the expense of water translocation. 3. Electron micrographic studies are interpreted to indicate that EDTA alone can cause condensation and dehydration of the mitochondrial matrix. However, both EDTA and substrate are necessary to remove appreciable quantities of water from mitochondrial intramembranous spaces. 4. Since the data in the accompanying report indicated that EDTA, in the absence of energy, decreased the permeability of mitochondrial membranes, it appears likely that ballooning of intramembranous spaces, following addition of EDTA, represents trapping of water between two semipermeable membranes following dehydration of mitochondrial matrix.

scholarly journals Rat liver mitochondria prepared in mannitol media demonstrate increased mitochondrial volumes compared with mitochondria prepared in sucrose media. Relationship to the effect of glucagon on mitochondrial function

1984 ◽  
Vol 221 (1) ◽  
pp. 147-152 ◽  
Author(s):  
D E Whipps ◽  
A P Halestrap
Keyword(s):  
Liver Mitochondria ◽  
Mitochondrial Metabolism ◽  
Rat Liver Mitochondria ◽  
Pyruvate Metabolism ◽  
Succinate Oxidation ◽  
Isolation Medium ◽  
Matrix Volume ◽  
Sucrose Medium ◽  
Mitochondrial Volume ◽  
Citrulline Synthesis

Liver mitochondria isolated from glucagon-treated rats by using both mannitol- and sucrose-based media showed enhanced uncoupled succinate oxidation, pyruvate metabolism and citrulline synthesis. Mitochondria prepared in mannitol medium showed some stimulation of these parameters compared with those prepared in sucrose medium. This was accompanied by an increase in matrix volume of about 20%. Some [14C]mannitol became permanently associated with mitochondria during preparation. It is suggested that mannitol may enter mitochondria during their preparation and cause swelling. The presence of 4mM-phosphate in the sucrose isolation medium stimulated the same parameters as did glucagon treatment, and also caused an increase in matrix volume of about 20%. These results confirm the conclusion that the mitochondrial volume may be important in the regulation of mitochondrial metabolism. They contradict the conclusion of others [Siess (1983) Hoppe-Seyler's Z. Physiol. Chem. 364, 279-290, 835-838] that mannitol rather than sucrose should be used when studying hormonal effects on mitochondrial metabolism. Reasons for the discrepancies in the results between groups studying the effects of hormones on mitochondrial metabolism are discussed.

scholarly journals SEDIMENTATION PROPERTIES OF RAT LIVER MITOCHONDRIA

1970 ◽  
Vol 46 (1) ◽  
pp. 17-26 ◽  
Author(s):  
John N. Loeb ◽  
Daniel V. Kimberg
Keyword(s):  
Rat Liver ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Electron Microscopic ◽  
Sucrose Density Gradient Centrifugation ◽  
Sedimentation Behavior ◽  
Sucrose Medium ◽  
Mitochondrial Volume

A prediction of the velocity of sedimentation of rat liver mitochondria in sucrose gradients is made on the basis of recent measurements of the size of isolated mitochondria suspended in sucrose medium and the model proposed by Bentzel and Solomon to describe the osmotic behavior of mitochondria. The experimentally observed velocity is extremely close to the predicted value and confirms by a different approach the estimate of mitochondrial volume made by Baudhuin and Berthet on the basis of electron microscopic measurements. Because cortisone treatment of rats is known to result in a marked increase in mitochondrial size as observed under the electron microscope, mitochondria were co-isolated from livers of control and cortisone-treated animals, and the sedimentation behavior of the mixtures was examined by sucrose density gradient centrifugation. Mitochondria from cortisone-treated animals were found to sediment 1.4 times as rapidly as those from control animals, indicating that their increased size cannot entirely be due to an increased imbibition of fluid from the surrounding sucrose medium, and that the change in size must at least in part be due to a change in content of nondiffusible mitochondrial components. Although the increase in sedimentation velocity of mitochondria from cortisone-treated animals is striking, it is less than that predicted solely on the basis of their size relative to that of control mitochondria. It is concluded that the increases in mitochondrial size and content of nondiffusible components produced by cortisone treatment are accompanied by alterations in mitochondrial composition as well.

scholarly journals Mitochondrial Swelling Induced by Glutathione

1959 ◽  
Vol 5 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Albert L. Lehninger ◽  
Marion Schneider
Keyword(s):  
Rat Liver ◽  
Potent Inhibitor ◽  
Reduced Glutathione ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Respiratory Inhibitors ◽  
Oxidation Reduction ◽  
Optimum Ph ◽  
High Concentrations

Reduced glutathione, in concentrations approximating those occurring in intact rat liver, causes swelling of rat liver mitochondria in vitro which is different in kinetics and extent from that yielded by L-thyroxine. The effect is also given by cysteine, which is more active, and reduced coenzyme A, but not by L-ascorbate, cystine, or oxidized glutathione. The optimum pH is 6.5, whereas thyroxine-induced swelling is optimal at pH 7.5. The GSH-induced swelling is not inhibited by DNP or dicumarol, nor by high concentrations of sucrose, serum albumin, or polyvinylpyrrolidone, in contrast to thyroxine-induced swelling. ATP inhibits the GSH swelling, but ADP and AMP are ineffective. Mn-+ is a very potent inhibitor, but Mg++ is ineffective. Ethylenediaminetetraacetate is also an effective inhibitor of GSH-induced swelling. The respiratory inhibitors amytal and antimycin A do not inhibit the swelling action of GSH, but cyanide does; these findings are consistent with the view that the oxidation-reduction state of the respiratory chain between cytochrome c and oxygen is a determinant of GSH-induced swelling. Reversal of GSH-induced swelling by osmotic means or by ATP in KCl media could not be observed. Large losses of nucleotides and protein occur during the swelling by GSH, suggesting that the action is irreversible. The characteristically drastic swelling action of GSH could be prevented if L-thyroxine was also present in the medium.

scholarly journals SWELLING OF FISH MITOCHONDRIA

1962 ◽  
Vol 13 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Thomas Richardson ◽  
A. L. Tappel
Keyword(s):  
Osmotic Pressure ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Rapid Rate ◽  
Mitochondrial Membranes ◽  
Fish Liver ◽  
Rapid Decay ◽  
Membrane Behavior ◽  
Slow Decay ◽  
Hypotonic Swelling

The physical properties of fish liver and rat liver mitochondria were compared as a function of temperature and osmotic pressure. The data indicate that fish mitochondria are more flexible and swell at a more rapid rate over a 0 to 30°C temperature range, whereas the rates of swelling at 30 to 40°C are comparable. The swelling rates of both fish and rat mitochondria vary with temperature and approximate the Arrhenius relationship. Apparent energies of activation for swelling averaged 26.5 kcal and 12.9 kcal for rat and fish, respectively. Fish mitochondria were less stable than rat mitochondria to osmotic variation, and the disparity in initial swelling rates became increasingly greater with lower osmotic pressure. The hypotonic swelling of both fish and rat mitochondria was readily reversed osmotically; however, there was a very rapid decay of reversal in fish mitochondria and only a very slow decay in the case of rat. All the data indicate that under comparable conditions the fish mitochondrial membranes are more flexible and presumably more permeable and labile than rat mitochondrial membranes. The findings are discussed in relation to the general metabolic implications and the possible contributions of the membrane constituents to membrane behavior.

scholarly journals Reversible sensitization and desensitization of carnitine palmitoyltransferase I to inhibition by malonyl-CoA in isolated rat liver mitochondria. Significance for the mechanism of malonyl-CoA-induced sensitization

1983 ◽  
Vol 214 (3) ◽  
pp. 1027-1030 ◽  
Author(s):  
V A Zammit
Keyword(s):  
Rat Liver ◽  
Reduced Glutathione ◽  
Thiol Group ◽  
Liver Mitochondria ◽  
Carnitine Palmitoyltransferase ◽  
Rat Liver Mitochondria ◽  
Nitrobenzoic Acid ◽  
Malonyl Coa ◽  
Carnitine Palmitoyltransferase I ◽  
Cpt I

Preincubation of rat liver mitochondria with 5,5′-dithiobis-(2-nitrobenzoic acid) (Nbs2) followed by removal of excess reagent by washing the mitochondria with 0.5 mM-reduced glutathione resulted in a desensitization of carnitine palmitoyltransferase (CPT) I activity to malonyl-CoA inhibition. The effect was not observed if mitochondria were washed with 0.5 mM-dithiothreitol. The desensitization effect of Nbs2 could be reversed by a second incubation in the presence of 8 microM-malonyl-CoA. In addition, malonyl-CoA, when present simultaneously with Nbs2, protected CPT I activity against the desensitization effect of the thiol-group reagent. These results suggest that malonyl-CoA exerts an effect on one or more thiol groups of the enzyme, and that this effect is related to the ability of the metabolite to sensitize CPT I to malonyl-CoA inhibition.

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