Mitochondrial permeability to chloride ion

1975 ◽  
Vol 228 (1) ◽  
pp. 122-126 ◽  
Author(s):  
MW Weiner

It is generally accepted that the inner membrane of the mitchondrion is not penetrated by chloride ion, in contrast to other biological membranes which are chloride permeable. In this report mitochondrial permeablity to chloride ion has been reevaluated by the measurement of passive swelling in isotonic chloride-containing solutions in the presence of an uncoupling agent. Under these conditions, mitochondria prepared from rat liver or beef heart show a definite uptake of wide variety of chloride salts. Mitochondrial chloride transport appears to be electrogenic, as is the transmembrane movement of the other halides. Therefore, the mitochondrial inner membrane shares with other biological membranes a definite permeability to this ubiquitous anion.

1992 ◽  
Vol 285 (1) ◽  
pp. 65-69 ◽  
Author(s):  
J Schlegel ◽  
M Schweizer ◽  
C Richter

It has recently been suggested by several investigators that the hydroperoxide- and phosphate-induced Ca2+ release from mitochondria occurs through a non-specific ‘pore’ formed in the mitochondrial inner membrane. The aim of the present study was to investigate whether ‘pore’ formation actually is required for Ca2+ release. We find that the t-butyl hydroperoxide (tbh)-induced release is not accompanied by stimulation of sucrose entry into, K+ release from, and swelling of mitochondria provided re-uptake of the released Ca2+ (‘Ca2+ cycling’) is prevented. We conclude that (i) the tbh-induced Ca2+ release from rat liver mitochondria does not require ‘pore’ formation in the mitochondrial inner membrane, (ii) this release occurs via a specific pathway from intact mitochondria, and (iii) a non-specific permeability transition (‘pore’ formation) is likely to be secondary to Ca2+ cycling by mitochondria.


1993 ◽  
Vol 289 (3) ◽  
pp. 703-708 ◽  
Author(s):  
S Echegoyen ◽  
E B Oliva ◽  
J Sepulveda ◽  
J C Díaz-Zagoya ◽  
M T Espinosa-García ◽  
...  

The effect of cholesterol incorporation on some functions of the mitochondrial inner membrane and on the morphology of rat liver mitochondria was studied. Basal ATPase and succinate dehydrogenase activities remained unchanged after cholesterol was incorporated into the mitochondria; however, uncoupled ATPase activity was partially inhibited. The presence of several substrates and inhibitors did not change the amount of cholesterol incorporated, which was localized mostly in the outer membrane. Electron-microscope observations revealed the presence of vesicles between the outer and inner membranes; these vesicles increased in number with the amount of cholesterol incorporated. The data suggest that cholesterol induces the formation of vesicles from the outer membrane, and modifies the activity of stimulated ATPase.


2002 ◽  
Vol 365 (2) ◽  
pp. 391-403 ◽  
Author(s):  
Lidia de BARI ◽  
Anna ATLANTE ◽  
Nicoletta GUARAGNELLA ◽  
Giovanni PRINCIPATO ◽  
Salvatore PASSARELLA

In the present study we investigated whether isolated rat liver mitochondria can take up and metabolize d-lactate. We found the following: (1) externally added d-lactate causes oxygen uptake by mitochondria [P/O ratio (the ratio of mol of ATP synthesized to mol of oxygen atoms reduced to water during oxidative phosphorylation) = 2] and membrane potential (Δψ) generation in processes that are rotenone-insensitive, but inhibited by antimycin A and cyanide, and proton release from coupled mitochondria inhibited by α-cyanocinnamate, but not by phenylsuccinate; (2) the activity of the putative flavoprotein (d-lactate dehydrogenase) was detected in inside-out submitochondrial particles, but not in mitochondria and mitoplasts, as it is localized in the matrix phase of the mitochondrial inner membrane; (3) three novel separate translocators exist to mediate d-lactate traffic across the mitochondrial inner membrane: the d-lactate/H+ symporter, which was investigated by measuring fluorimetrically the rate of endogenous flavin reduction, the d-lactate/oxoacid antiporter (which mediates both the d-lactate/pyruvate and d-lactate/oxaloacetate exchanges) and d-lactate/malate antiporter studied by monitoring photometrically the appearance of the d-lactate counteranions outside mitochondria. The d-lactate translocators, in the light of their different inhibition profiles separate from the monocarboxylate carrier, were found to differ from each other in the Vmax values and in the inhibition and pH profiles and were shown to regulate mitochondrial d-lactate metabolism in vitro. The d-lactate translocators and the d-lactate dehydrogenase could account for the removal of the toxic methylglyoxal from cytosol, as well as for d-lactate-dependent gluconeogenesis.


1972 ◽  
Vol 129 (1) ◽  
pp. 39-54 ◽  
Author(s):  
P. C. Holland ◽  
H. S. A. Sherratt

1. The hypoglycaemic compound diphenyleneiodonium causes rapid and extensive swelling of rat liver mitochondria suspended in 150mm-NH4Cl, and in 150mm-KCl in the presence of 2,4-dinitrophenol and valinomycin. This indicates that diphenyleneiodonium catalyses a compulsory exchange of OH-for Cl-across the mitochondrial inner membrane. Br-and SCN-were the only other anions found whose exchange for OH-is catalysed by diphenyleneiodonium. 2. Diphenyleneiodonium inhibited state 3 respiration of mitochondria and slightly stimulated state 4 respiration with succinate or glutamate as substrate in a standard Cl--containing medium. 3. Diphenyleneiodonium did not inhibit state 3 respiration significantly in two Cl--free media (based on glycerol 2-phosphate or sucrose) but caused some stimulation of state 4. 4. In Cl--containing medium diphenyleneiodonium only slightly inhibited the 2,4-dinitrophenol-stimulated adenosine triphosphatase and it had little effect in the absence of Cl-. 5. The inhibition of respiration in the presence of Cl-is dependent on the Cl-–OH-exchange. 2,4-Dichlorodiphenyleneiodonium is ten times as active as diphenyleneiodonium both in causing swelling of mitochondria suspended in 150mm-NH4Cl and in inhibiting state 3 respiration in Cl--containing medium. Indirect evidence suggests that the Cl-–OH-exchange impairs the rate of uptake of substrate anions. 6. It is proposed that stimulation of state 4 respiration in the absence of Cl-depends, at least in part, on an electrogenic uptake of diphenyleneiodonium cations. 7. Tripropyl-lead acetate, methylmercuric iodide and nine substituted diphenyleneiodonium derivatives also catalyse Cl-–OH-exchange across the mitochondrial membrane. 8. Diphenyleneiodonium is compared with the trialkyltin compounds, which are also known to mediate Cl-–OH-exchange and which have in addition strong oligomycin-like effects on respiration. It is concluded that diphenyleneiodonium is specific for catalysing anion–OH-exchange and will be a useful reagent for investigating membrane-dependent systems.


1987 ◽  
Vol 41b ◽  
pp. 770-772 ◽  
Author(s):  
Vigg Joste ◽  
Jean-Marc Berrez ◽  
Norbert Latruffe ◽  
B. Dean Nelson ◽  
Michael Sjöström

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