D-Lactate altered mitochondrial energy production in rat brain and heart but not liver

Nutrition & Metabolism

Table 4 Respiratory parameters^a of isolated rat brain and liver mitochondria with pyruvate, D-lactate, L-lactate as substrates in the presence of oxamate, a LDH inhibitor.

Substrate^b	Tissue	State 4	State 3	RCI
Pyruvate + OX	Brain	3.20 ± 0.57	17.96 ± 2.51	5.74 ± 0.41
	Liver	2.61 ± 0.09	9.98 ± 0.31	3.83 ± 0.05
LLA + OX	Brain	3.45 ± 0.12	4.27 ± 0.35	1.23 ± 0.06
	Liver	3.28 ± 0.23	4.19 ± 1.08	1.25 ± 0.23
DLA + OX	Brain	3.25 ± 0.15	4.83 ± 1.11	1.47 ± 0.30
	Liver	4.11 ± 0.15	14.34 ± 0.21	3.50 ± 0.12
Pyr +LLA+ OX	Brain	3.06 ± 0.42	7.14 ± 1.23	2.32 ± 0.14
	Liver	2.16 ± 0.22	2.73 ± 0.45	1.29 ± 0.25

^aRespiratory rates in nmol O₂/mg mitochondrial protein per min.
^bSubstrate concentrations: pyruvate (10 mM + 2.5 mM malate) and LLA or DLA (5 mM + 2.5 mM malate); OX, oxamate (50 mM).
State 4: The respiration state without ADP.
State 3: The respiration state with the addition of ADP.
RCR: Respiratory Control Ratio (state 3 rate:state 4 rate).
ADP/O ratio: The ratio between the amount of ADP phosphorylated and oxygen consumed.
*Significantly different from the values without substrate. Values were compared using one way ANOVA with LSD as post hoc test. α < 0.05
Note: Refer to Table 1 and 2 for the respiratory parameters without substrates or with cocktail.

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