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.
Department of Biochemistry, Faculty of Science, M. S. University of Baroda, India.
M S
MS
Jani
S D
SD
Telang
S S
SS
Katyare
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