OXIDATIVE PHOSPHORYLATION BY MUSCLE MITOCHONDRIA OF DYSTROPHIC MICE

1967 ◽  
Vol 45 (8) ◽  
pp. 1271-1278 ◽  
Author(s):  
Klaus Wrogemann ◽  
M. C. Blanchaer

Oxidative phosphorylation was studied in mitochondria isolated from the skeletal muscle of control and dystrophic mice of the Jackson Laboratory strain 129/Re, aged 32–104 days. The isolation procedure included a preliminary incubation of the muscle minced in a medium containing a proteinase (Nagarse) followed by gentle homogenization and differential centrifugation. Polarographic estimations in the presence and absence of adenosine diphosphate (ADP) indicated that the rate of oxygen uptake, ADP/0 ratio, respiratory control ratio, and phosphorylation rate were not significantly different in the mitochondria isolated from control and dystrophic mice. Bovine serum albumin increased the ADP/0 and respiratory control ratios, but the values for the control and dystrophic preparations again did not differ significantly in the presence of albumin.

1968 ◽  
Vol 46 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Klaus Wrogemann ◽  
M. C. Blanchaer

Mitochondria isolated from skeletal muscle and heart of normal Syrian hamsters and from hamsters of the BIO 14.6 myopathic strain aged 97–124 days were studied. Histological examination of the tissues and serum creatine phosphokinase determinations established that the disease was active in the dystrophic animals. In the mitochondrial isolation procedure the minced tissue was incubated before homogenization in a mannitol–sucrose–EDTA medium containing a proteinase (Nagarse). Polarographic estimations with pyruvate–malate as substrate, in the presence and absence of ADP, indicated that the rate of O2 uptake, ADP/O ratio, and respiratory control ratio (state 3 to 4 transition) of the heart mitochondria did not suffer significantly between the normal and myopathic groups. The findings with the skeletal muscle mitochondria were similar. L-α-Glycerophosphate oxidation also was not affected by the myopathy but the rate of NADH oxidation was 35% slower in the heart mitochondria of the BIO 14.6 strain.


2010 ◽  
Vol 2010 ◽  
pp. 1-6
Author(s):  
Noriaki Kaneko ◽  
Tetsuya Rikimaru ◽  
Tetsuyuki Fujimura ◽  
Shigeyasu Mori ◽  
Saburo Hidaka ◽  
...  

In order to establish a method of obtaining rat gingival mitochondria (Mt), Mt fractions were prepared in various combinations of homogenizing time with collagenase concentration. Rat gingival tissues were excised, minced, treated with collagenase, homogenized, and subjected to differential centrifugation rates. Both the respiratory control ratio (RCR) and adenosine diphosphate/oxygen (ADP/O) ratio of the Mt fraction prepared in a combination of 40, 50, or 60 sec homogenization with collagenase in a concentration range of 0.115%–0.130% (w/v) were measured. The values for the RCR and ADP/O ratio of the Mt fraction obtained in an optimal condition was and , respectively. These results suggest that Mt of fairly high quality can be obtained through this refined combination of the homogenizing time and collagenase concentration.


1969 ◽  
Vol 15 (8) ◽  
pp. 975-977 ◽  
Author(s):  
K. Watson ◽  
W. Paton ◽  
J. E. Smith

Mitochondria isolated from Aspergillus oryzae exhibited respiratory control with a range of substrates. Bovine serum albumin was required in the reaction medium to observe adenosine diphosphate (ADP) controlled respiration. The mitochondria carried out active oxidation and phosphorylation with citrate as substrate in the pH range 6–7 and showed a slight optimum for oxidative phosphorylation at pH 6.5. The respiratory properties of the isolated mitochondria were similar to those reported for A. niger and yeast mitochondria.


2016 ◽  
Vol 62 (5) ◽  
pp. 572-576 ◽  
Author(s):  
T.A. Popova ◽  
V.N. Perfilova ◽  
G.A. Zhakupova ◽  
V.E. Verovsky ◽  
O.V. Ostrovskij ◽  
...  

Substitution of drinking water for 1.8% NaCl in pregnant rats caused a pronounced increase in arterial pressure by 24,3% and urinary protein by 117% to day 21 of pregnancy. State 4 respiration of isolated placental mitochondria in the group of negative control was 3- and 1.5-fold higher with malate/glutamate and succinate as substrates than in placental mitochondria isolated from uncomplicated pregnant animals. This led to a decrease of the respiratory control ratio. These results suggest that development of experimental preeclampsia is accompanied by mitochondrial dysfunction through uncoupling of oxidative phosphorylation. Daily administration of sulodexide to females with experimental preeclampsia (EP) per os at a dose of 30 LE during the whole period of gestation decreased manifestations of the disease as evidenced by a slight increase in blood pressure (by 8,6%) and less pronounces increase in urinary protein (by 58,9%). Sulodexide decreased development of mitochondrial dysfunction in EP rats as shown a decrease of non-stimulated ADP respiration with malate/glutamate and succinate (4.5- and 2.5-fold, respectively) as compared with the negative control group and the corresponding increase in the respiratory control ratio (2.5- and 1.5-fold, respectively). Thus, sulodexide reduces uncoupling of oxidative phosphorylation and enhances the functional activity of mitochondria in EP animals, possibly due to its antioxidant and endotelioprotective effects.


Author(s):  
R. F. Dunn ◽  
M. Worsfold ◽  
J. B. Peter

This is a preliminary report on our studies correlating the morphology and biochemical characteristics of mitochondria isolated from rat skeletal muscle. Figures 1 to 3 show sections of the mitochondrial preparations made on two separate occasions. These were sedimented from low speed supernatants at 3,500 g for 10 minutes (Figs. 1 and 2) or from a 3,500 g supernatant sedimented at 7,000 g for 10 minutes (Fig. 3). Polarographic traces of the respiration of the 3,500 g fractions from the two preparations, with pyruvate and malate as substrates, are shown in Figure 4.The mitochondria in the 70-3,500 g fraction from rat A (Fig. 1) were generally compact with closely packed cristae. Contamination with myofibrillar material was evident. In the 7,000 g fraction from the same animal, very few myofibrils were seen, and the mitochondria appeared distended and generally swollen (Fig. 3). The respiratory control ratio (RCR) of the 3,500 g mitochondria (Fig. 1) was 3.1 compared to 2.2 of the 7,000 g fraction (Fig. 3). Using our technique of preparation most of the mitochondria from rat skeletal muscle were sedimented at 3,500 g.


1988 ◽  
Vol 66 (3) ◽  
pp. 376-379 ◽  
Author(s):  
J. H. Thakar ◽  
M. N. Hassan

The catecholamine neurotoxin 6-hydroxydopamine (6-OHDA) has been used to produce cardiac chemical sympathectomy as well as a model of parkinsonism. Several mechanisms have been proposed to explain its cytotoxicity, including the productions of quinones, hydrogen peroxide, and free radicals by autooxidation and the uncoupling of mitochondrial oxidative phosphorylation. We have observed that 6-OHDA at a concentration of 0.05 mM rapidly consumes oxygen from the mitochondrial incubation medium but does not affect oxidative phosphorylation in the mitochondria from rat striatum, cortex, and liver. At the higher concentration of 0.5 mM, 6-OHDA consumes all of the available oxygen from the incubation medium. Mitochondria exposed to this concentration of 6-OHDA show decreases in the respiratory control ratio and adenosine triphosphate synthesis as measured by the consumption ratio of ADP to oxygen. Thus, only the higher (0.5 mM) concentration of 6-OHDA, which produces anoxia in vitro, also causes mitochondrial damage.


1975 ◽  
Vol 21 (6) ◽  
pp. 877-883 ◽  
Author(s):  
G. Gordon Greer ◽  
F. H. Milazzo

The addition of Pseudomonas aeruginosa KCIIR LPS to respiring mitochondria stimulated the rate of substrate oxidation, reduced the respiratory control ratio, stimulated oxygen uptake in state 4, and released the inhibition imposed upon state 3 by atractyloside. It was concluded that LPS acted as an uncoupler of oxidative phosphorylation and that it produced effects similar to those observed with the classical uncoupler 2,4-dinitrophenol.


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