Response of Oxidative Phosphorylation in Liver of Protein-Energy Malnourished Rats

Ramanadham, M.; Kaplay, Suresh S.

doi:10.1159/000176261

Cited by 7 publications

(2 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Together, these studies suggest that caloric restriction induces a "passive" adaptation of energy metabolism (because of organ weight loss) as well as a "dynamic" adaptation (visceral organs energy expenditure becomes more reduced than expected for their given weight loss). This metabolic adaptation therefore implicates decreased mitochondrial oxygen consumption as found during mediumterm (several weeks) food restriction [9][10][11]. This decrease in mitochondrial respiration could be partly explained by a reduced Na + -K + -ATPase activity [9], or by a decrease in cytochrome a + a 3 content [10].…”

Section: Introductionmentioning

confidence: 88%

Food restriction affects energy metabolism in rat liver mitochondria

Dumas

2004

Biochimica et Biophysica Acta (BBA) - General Subjects

View full text Add to dashboard Cite

To examine the effect of 50% food restriction over a period of 3 days on mitochondrial energy metabolism, liver mitochondria were isolated from ad libitum and food-restricted rats. Mitochondrial enzyme activities and oxygen consumption were assessed spectrophotometrically and polarographically. With regard to body weight loss (-5%), food restriction decreased the liver to body mass ratio by 7%. Moreover, in food-restricted rats, liver mitochondria displayed diminished state 3 (-30%), state 4-oligomycin (-26%) and uncoupled state (-24%) respiration rates in the presence of succinate. Furthermore, "top-down" elasticity showed that these decreases were due to an inactivation of reactions involved in substrate oxidation. Therefore, it appears that rats not only adapt to food restriction through simple passive mechanisms, such as liver mass loss, but also through decreased mitochondrial energetic metabolism

show abstract

Section: Introductionmentioning

confidence: 88%

Food restriction affects energy metabolism in rat liver mitochondria

Dumas

2004

Biochimica et Biophysica Acta (BBA) - General Subjects

View full text Add to dashboard Cite

show abstract

“…Details of the diet compositions and rats used in these studies have been reported earlier [13,14]. Briefly, wealing Wistar strain male rats were fed a 22% casein diet till they attained an average body weight of 90 g. They were then divided into 3 groups.…”

Section: Methodsmentioning

confidence: 99%

Modified Kidney Sodium Potassium Adenosine-Triphosphatase Kinetics in Protein Energy Malnutrition

Samiuddin

Rao

1986

J. Clin. Biochem. Nutr.

View full text Add to dashboard Cite

SummaryErythrocyte membrane and kidney microsomal Na, KATPases have been shown to be elevated in children suffering from kwashiorkor and in protein energy malnourished (PEM) rats. Kinetic properties of kidney microsomal Na, K-ATPase were studied in PEM rats to understand further the mechanism of this elevated activity. From the Arrhenius plots no significant differences were seen in the critical temperature and energy of activation of Na, K-ATPase between the control (C), energyrestricted (ER), and protein-restricted (PR) rats. Changes in the apparent K0.5 values of Nat, K+, and ATP were of much smaller magnitude, and increased Vmax was found to be mainly responsible for the observed increase in Na, K-ATPase activity in PEM rats. The Hill coefficient with ATP as substrate was found to be 1.62 in all three groups. Vmax/Km : a broad index of physiological efficiency, remained unaltered with K+ as a substrate in the ER rats, but was higher by 60% in PR rats as compared with the control value. In the Nat-activated component, the physiological efficiency in protein restriction was higher by 60% in relation to energy restriction. These results lead to the conclusion that the increased Na, K-ATPase activity in kidney microsomal preparations, from PR rats is attributable to modifications in the enzyme site and that energy restriction, in fact, results in a lowering of the physiological efficiency of Na, KATPase by affecting the Nat-site. Altered lipid microenvironment if any, does not appear to contribute to changes in Na, K-ATPase activity in PEM since neither Arrhenius plots nor Hill coefficients (ATP) showed any modification.

show abstract

Protein Restriction Without Strong Caloric Restriction Decreases Mitochondrial Oxygen Radical Production and Oxidative DNA Damage in Rat Liver

Sanz

Caro

Barja

2004

J Bioenerg Biomembr

125

View full text Add to dashboard Cite

Previous studies have shown that caloric restriction decreases mitochondrial oxygen radical production and oxidative DNA damage in rat organs, which can be linked to the slowing of aging rate induced by this regime. These two characteristics are also typical of long-lived animals. However, it has never been investigated if those decreases are linked to the decrease in the intake of calories themselves or to decreases in specific dietary components. In this study the possible role of the dietary protein was investigated. Using semipurified diets, the ingestion of proteins of Wistar rats was decreased by 40% below that of controls while the other dietary components were ingested at the same level as in animals fed ad libitum. After seven weeks in this regime the liver of the protein restricted animals showed 30-40% decreases in mitochondrial production of reactive oxygen species (ROS) and in oxidative damage to nuclear and mitochondrial DNA. The decreases in ROS generation occurred specifically at complex I. They also occurred without changes in mitochondrial oxygen consumption. Instead, there was a decrease in the percent free radical leak (the percentage of total electron flow leading to ROS generation in the respiratory chain). These results are strikingly similar to those previously obtained after 40% caloric restriction in the liver of Wistar rats. Thus, the results suggest that part of the decrease in aging rate induced by caloric restriction can be due to the decreased intake of proteins acting through decreases in mitochondrial ROS production and oxidative DNA damage. Interestingly, these tissue oxidative stress-linked parameters can be lowered by restricting only the intake of dietary protein, probably a more feasible option than caloric restriction for adult humans.

show abstract

Response of Oxidative Phosphorylation in Liver of Protein-Energy Malnourished Rats

Cited by 7 publications

References 13 publications

Food restriction affects energy metabolism in rat liver mitochondria

Food restriction affects energy metabolism in rat liver mitochondria

Modified Kidney Sodium Potassium Adenosine-Triphosphatase Kinetics in Protein Energy Malnutrition

Protein Restriction Without Strong Caloric Restriction Decreases Mitochondrial Oxygen Radical Production and Oxidative DNA Damage in Rat Liver

Contact Info

Product

Resources

About