The Effects of Pent-4-enoate and Methylenecyclopropylacetate on some Enzymes of β-Oxidation in Rat Liver Mitochondria in vivo and in vitro

1975 ◽  
Vol 3 (2) ◽  
pp. 331-333 ◽  
Author(s):  
HARALD OSMUNDSEN ◽  
DAVID BILLINGTON ◽  
H. STANLEY ◽  
A. SHERRATT
Keyword(s):  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria

Import of the glucocorticoid receptor into rat liver mitochondria in vivo and in vitro

1993 ◽  
Vol 46 (3) ◽  
pp. 401-413 ◽  
Author(s):  
C. Demonacos ◽  
N.C. Tsawdaroglou ◽  
R. Djordjevic-Markovic ◽  
M. Papalopoulou ◽  
V. Galanopoulos ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria

scholarly journals Selective permeability of rat liver mitochondria to purified aspartate aminotransferases in vitro

1977 ◽  
Vol 164 (3) ◽  
pp. 685-691 ◽  
Author(s):  
E Marra ◽  
S Doonan ◽  
C Saccone ◽  
E Quagliariello
Keyword(s):  
Rat Liver ◽  
Aspartate Aminotransferase ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Transferase Activity ◽  
Selective Permeability ◽  
The Matrix ◽  
Mitochondrial Aspartate Aminotransferase

1. A method was devised to allow determination of intramitochondrial aspartate amino-transferase activity in suspensions of intact mitochondria. 2. Addition of purified rat liver mitochondrial aspartate aminotransferase to suspensions of rat liver mitochondria caused an apparent increase in the intramitochondrial enzyme activity. No increase was observed when the mitochondria were preincubated with the purified cytoplasmic isoenzyme. 3. These results suggest that mitochondrial aspartate aminotransferase, but not the cytoplasmic isoenzyme, is able to pass from solution into the matrix of intact rat liver mitochondria in vitro. 4. This system may provide a model for studies of the little-understood processes by which cytoplasmically synthesized components are incorporated into mitochondria in vivo.

Oxidative phosphorylation and adenosine triphosphatase activity in the liver mitochondria of rats administered with phenylhydrazine and hydroiyzed glucose cycloacetoacetate

1969 ◽  
Vol 47 (3) ◽  
pp. 297-300 ◽  
Author(s):  
T. G. Reddi ◽  
M. C. Nath
Keyword(s):  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
Rat Liver ◽  
Adenosine Triphosphatase ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Partial Restoration ◽  
Atp Formation

The effect of phenylhydrazine and hydroiyzed product of glucose cycloacetoacetate (GCAh) administration on the activity of adenosine triphosphatase (ATPase) in rat-liver mitochondria has been investigated. The results are discussed in relation to the efficiency of mitochondrial oxidative phosphorylation. Phenylhydrazine was found to increase the ATPase activity both in vitro and in vivo. However, preincubation or treatment with hydrolyzed glucose cycloacetoacetate resulted in an appreciable depression of this phenylhydrazine-enhanced enzyme activity. The liver mitochondria from phenylhydrazine-administered rats showed very little difference in milligrams of total protein, but the homogenates had a high protein content as compared to the preparations from normal rats and rats administered with hydrolyzed glucose cycloacetoacetate. With citrate as the substrate, normal rat-liver mitochondria exhibited a P/O ratio of 3.0. With the same substrate, the liver mitochondria from phenylhydrazine-administered rats lowered the oxygen uptake and ATP formation, thereby resulting in a decreased P/O ratio of 2.4, whereas administration of hydrolyzed glucose cycloacetoacetate prior to phenylhydrazine resulted in a partial restoration in oxygen uptake and ATP formation, and thus yielded a P/O ratio of 2.8.

HETEROGENEITY AND DIFFERENTIAL FRAGILITY OF RAT LIVER MITOCHONDRIA

1966 ◽  
Vol 44 (5) ◽  
pp. 497-508 ◽  
Author(s):  
C. V. Lusena ◽  
Florent Depocas
Keyword(s):  
Rat Liver ◽  
High Speed ◽  
Specific Activity ◽  
Mitochondrial Protein ◽  
Total Activity ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Fraction I

Five fractions (I–V) of intact mitochondria were obtained from rat liver by differential centrifugation during isolation. They represented respectively 4, 9, 64, 11, and 11% of the total mitochondrial protein. No striking differences between mitochondria sedimented at low speed (fraction I) and those sedimented at high speed (fraction V) were seen by electron microscopy. In all samples glutamic dehydrogenase (GD) specific activity was the same after deoxycholate treatment and less than 1% of the total activity could be detected in the fresh fractions. Overnight freezing at −5 °C of fractions I, III, and V followed by thawing at 37 °C liberated 25, 11, and 6% respectively of the total GD activity. The greater fragility of fraction I relative to that of fraction V was also apparent in the phase-contrast microscope during warming to room temperature; lysis occurred in 10 minutes in fraction I and in 1 hour in fraction V. The distribution of GD activity after centrifugation on sucrose density gradients indicated that partial disruption of the mitochondria had occurred in decreasing degree from fractions I to V. The different fragilities of the fractions in vitro did not reflect different lability in vivo since all fractions had the same rates of turnover as measured after they were labeled with14C acetate. The results are discussed in terms of heterogeneities observed by other methods.

Sign in / Sign up

Export Citation Format

Share Document