Effect of corticosterone treatment on energy metabolism in rat liver mitochondria.
1. Effect of in vivo treatment (40 mg/kg body wt) with corticosterone on energy metabolism in rat liver mitochondria was examined under acute and chronic conditions in 20-, 35- and 60-day-old rats. 2. Acute treatment did not affect body or liver weight. However, chronic treatment caused increased liver weight in the former two age groups; in the 60-day-old animals the liver weight decreased. 3. Acute treatment resulted in a generalized decrease in state 3 respiration rates and state 4 respiration rates without having any significant effect on ADP/O ratios with glutamate, succinate and ascorbate + TMPD as substrates. However, rates of ATP synthesis decreased significantly. The effect was age-dependent, older animals showed increased resistance. 4. Chronic treatment resulted in uncoupling of oxidative phosphorylation without having significant effects on respiration rates. Once again, the effects were age-dependent. Consequently, the ATP synthesis rates were significantly lowered. However, it was apparent that the underlying mechanisms were entirely different. 5. With succinate as the substrate the state 3 respiration rates increased with age to reach adult values by day 60. The coupling efficiency was also exhibited via maturational changes.
Jani
M S
MS
Department of Biochemistry, Faculty of Science, M. S. University of Baroda, India.
Telang
S D
SD
Katyare
S S
SS
D000244:Adenosine Diphosphate / Q000378:metabolism; D000375:Aging / Q000378:metabolism; D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D003345:Corticosterone / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects*; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D008099:Liver / Q000187:drug effects; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D010085:Oxidative Phosphorylation / Q000187:drug effects; D051381:Rats; D013386:Succinates / Q000378:metabolism; D019802:Succinic Acid; D013772:Tetramethylphenylenediamine / Q000378:metabolism
D005971:Glutamates; D013386:Succinates; D018698:Glutamic Acid; D000244:Adenosine Diphosphate; D019802:Succinic Acid; D013772:Tetramethylphenylenediamine; D001205:Ascorbic Acid; D003345:Corticosterone