2-Ethylhexanoic acid inhibits urea synthesis and stimulates carnitine acetyltransferase activity in rat liver mitochondria

1989 ◽  
Vol 63 (2) ◽  
pp. 160-161 ◽  
Author(s):  
A. Manninen ◽  
S. Kr�ger ◽  
J. Liesivuori ◽  
H. Savolainen
Keyword(s):  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Urea Synthesis ◽  
Carnitine Acetyltransferase ◽  
Acetyltransferase Activity

scholarly journals The regulation of carbamoyl phosphate synthase activity in rat liver mitochondria

1976 ◽  
Vol 154 (2) ◽  
pp. 415-421 ◽  
Author(s):  
J D. McGivan ◽  
N M. Bradford ◽  
J Mendes-Mourão
Keyword(s):  
Protein Content ◽  
Nitrogen Source ◽  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Urea Synthesis ◽  
Carbamoyl Phosphate ◽  
Citrulline Synthesis ◽  
Ornithine Transcarbamoylase ◽  
Phosphate Synthase

The rate at which isolated rat liver mitochondria synthesized citrulline with NH4C1 as nitrogen source was markedly dependent on the protein content of the diet. 2. Citrulline synthesis was not rate-limited by substrate concentration, substrate transport or ornithine transcarbamoylase activity under the conditions used. 3. The intramitochondrial content of an activator of carbamoyl phosphate synthase, assumed to be N-acetyl-glutamate, varied markedly with dietary protein content. The variation in the concentration of this activator was sufficient to account for the observed variation in the rates of citrulline synthesis if this synthesis were rate-limited by the activity of carbamoyl phosphate synthase. 4. The rates of urea formation from NH4Cl as nitrogen source in isolated liver cells showed variations in response to diet that closely paralleled the variations in the rates of citrulline synthesis observed in isolated mitochondria. 5. These results are consistent with the postulate that when NH4Cl plus ornithine are present in an excess, the rate of urea synthesis is regulated at the level of carbamoyl phosphate synthase activity.

scholarly journals Aspects of carnitine ester metabolism in sheep liver

1970 ◽  
Vol 119 (1) ◽  
pp. 59-65 ◽  
Author(s):  
A. M. Snoswell ◽  
G. D. Henderson
Keyword(s):  
Rat Liver ◽  
Bovine Liver ◽  
Liver Mitochondria ◽  
Free Carnitine ◽  
Rat Liver Mitochondria ◽  
Carnitine Acetyltransferase ◽  
Total Acid ◽  
Sheep Liver ◽  
Ad Libitum ◽  
Carnitine Palmitoyltransferase Activity

1. Carnitine acetyltransferase (EC 2.3.1.7) activity in sheep liver mitochondria was 76nmol/min per mg of protein, in contrast with 1.7 for rat liver mitochondria. The activity in bovine liver mitochondria was comparable with that of sheep liver mitochondria. Carnitine palmitoyltransferase activity was the same in both sheep and rat liver mitochondria. 2. The [free carnitine]/[acetylcarnitine] ratio in sheep liver ranged from 6:1 for animals fed ad libitum on lucerne to approx. 1:1 for animals grazed on open pastures. This change in ratio appeared to reflect the ratio of propionic acid to acetic acid produced in the rumen of the sheep under the two dietary conditions. 3. In sheep starved for 7 days the [free carnitine]/[acetylcarnitine] ratio in the liver was 0.46:1. The increase in acetylcarnitine on starvation was not at the expense of free carnitine, as the amounts of free carnitine and total acid-soluble carnitine rose approximately fivefold on starvation. An even more dramatic increase in total acid-soluble carnitine of the liver was seen in an alloxan-diabetic sheep. 4. The [free CoA]/[acetyl-CoA] ratio in the liver ranged from 1:1 in the sheep fed on lucerne to 0.34:1 for animals starved for 7 days. 5. The importance of carnitine acetyltransferase in sheep liver and its role in relieving `acetyl pressure' on the CoA system is discussed.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

Energy and Antioxidant Status of Rat Liver Mitochondria during Hypoxia- Reoxygenation of Different Duration

2016 ◽  
Vol 7 (4) ◽  
pp. 349-361
Author(s):  
Olga A. Gonchar ◽  
Valentina I. Nosar ◽  
Larisa. V. Bratus ◽  
I. N. Tymchenko ◽  
N. N. Steshenko ◽  
...  
Keyword(s):  
Rat Liver ◽  
Antioxidant Status ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Hypoxia Reoxygenation
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