Abstract
The observation in this laboratory that respiration and Sr2+ import were stimulated by the addition of 3-hydroxybutyrate to suspensions of N-ethylmaleimide-treated mitochondria respiring in state 6, after the addition of Sr2+, in a sucrose medium containing choline as substrate, led to the proposal by Moyle and Mitchell [(1977) FEBS Lett. 84, 135-140] that there is a Ca2+(Sr2+)-3-hydroxybutyrate symporter in rat liver mitochondria. However, experiments described in the present paper support a different interpretation. Under the conditions of the experiments by Moyle and Mitchell, the rate of respiration and the poise of Sr2+ accumulation are mainly limited, not by delta mu H+, but by lack of respiratory substrate. Even though N-ethylmaleimide is a potent inhibitor of 3-hydroxybutyrate dehydrogenase, we have found that, somewhat surprisingly, under the special conditions of these experiments, sufficient 3-hydroxybutyrate dehydrogenase activity remains available to account for the 3-hydroxybutyrate-dependent respiratory stimulation and Sr2+ import.
Original language | English |
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Pages (from-to) | 243-249 |
Number of pages | 0 |
Journal | Eur J Biochem |
Volume | 157 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2 Jun 1986 |
Keywords
- 3-Hydroxybutyric Acid
- Acetoacetates
- Animals
- Biological Transport
- Active
- Butyrates
- Butyric Acid
- Calcimycin
- Calcium
- Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone
- Ethylmaleimide
- Hydrogen-Ion Concentration
- Hydroquinones
- Hydroxybutyrate Dehydrogenase
- Hydroxybutyrates
- Mitochondria
- Liver
- Oxygen Consumption
- Rats
- Rotenone
- Strontium
- Time Factors