Lactate dehydrogenase in rat mitochondria

Brandt, Richard B.; Laux, Jerome E.; Spainhour, Stephen E.; Kline, Edward S.

doi:10.1016/0003-9861(87)90507-8

Cited by 87 publications

(78 citation statements)

References 20 publications

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“…7). These data are fully consistent with the "persistent" level of protease-inaccessible mitochondrial LDH in rat liver, kidney, and heart described by Brandt et al (16) over 25 years ago. The data in the current study are also consistent with the notion of significant amounts of LDH bound to the OMM, as well as localized to the mitochondrial intermembrane space (16).…”

Section: Discussionsupporting

confidence: 91%

Physical and Functional Association of Lactate Dehydrogenase (LDH) with Skeletal Muscle Mitochondria

Elustondo

White²,

Hughes³

et al. 2013

Journal of Biological Chemistry

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Background:The notion of mitochondrial lactate oxidation in skeletal muscle is controversial. Results: Mitochondrial respiration increased in the presence of substrates and cofactors for the lactate dehydrogenase (LDH) reaction. Respiration was inhibited when mitochondrial pyruvate transport was blocked. Conclusion: Extra-matrix LDH is associated with muscle mitochondria. Significance: LDH is strategically positioned within skeletal muscle fibers to functionally interact with mitochondria.

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Section: Discussionsupporting

confidence: 91%

Physical and Functional Association of Lactate Dehydrogenase (LDH) with Skeletal Muscle Mitochondria

Elustondo

White²,

Hughes³

et al. 2013

Journal of Biological Chemistry

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“…Skeletal muscle LDH has been observed to be localized in sarcoplasmic reticulum (e.g., Baba and Sharma 1971) and mitochondria (Baba and Sharma 1971;Lluis 1984;Szcz sna-Kaczmarek 1990). Mitochondria isolated from liver also contain LDH (e.g., Brandt et al 1987). Furthermore, there is the possibility that differences in mitochondrial volume densities are responsible for the diverse a values for LDH in various cell types (Nakae and Stoward 1994a).…”

Section: Discussionmentioning

confidence: 99%

Effects of Tissue Protectants on the Kinetics of Lactate Dehydrogenase in Cells

Nakae

Stoward

1997

J Histochem Cytochem.

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SUMMARYWe studied the effects of two tissue protectants, polyvinyl alcohol (PVA) and agarose gel, on a kinetic parameter of lactate dehydrogenase LDH that is assumed to be related to the extent of diffusion of the enzyme out of tissue sections during its histochemical assay. The kinetics of the enzyme in mouse gastrocnemius (skeletal) muscle fibers and periportal hepatocytes were determined in unfixed sections incubated either on substrate ( L -lactate)-containing agarose gel films or in aqueous assay media in the presence or absence of 18% PVA. The absorbances of the formazan final reaction products at their isobestic point were measured continuously in the cytoplasm of individual cells as a function of incubation time, using a real-time image analysis system. Whichever incubation medium was used, the absorbances in the two cell types increased nonlinearly during the first minute of incubation but linearly for incubation times between 1 and 3 min. The nonlinearity of the LDH reaction was analyzed using the equation v i Ϫ v ϭ a Њ A , where v i is the observed initial velocity determined from the absorbance changes during the first 10 sec of incubation and v and Њ A are respectively the gradient and intercept on the absorbance axis of the linear regression line of the absorbance on incubation times between 1 and 3 min. The plots of the observed ( v i Ϫ v ) against Њ A were linear. Their gradients a were characteristic for each cell type and tissue protectant. The a values for skeletal muscle fibers were 12-43% lower than those for hepatocytes. The a value for hepatocytes obtained with the PVA method was 32% lower than that determined with the gel film method. For skeletal muscle fibers, the a values determined by the two methods were almost the same. Addition of excess pyruvate to the aqueous assay medium had no effects on a for either muscle fibers or hepatocytes. In contrast, a was zero for sections of polyacrylamide gels containing purified enzyme, whether incubated on agarose films or in PVA media. These data confirmed that the constant a is related to the extent to which the enzyme diffuses out of sections during incubation but not to product inhibition of LDH by pyruvate. PVA was more effective for protecting diffusion of LDH from hepatocytes than from skeletal muscle fibers, possibly because hepatocytes contain a greater proportion of diffusable (unbound) LDH than skeletal muscle fibers.

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“…Consequently, lactate formation from pyruvate takes place within an aggregate of glycolytic enzymes, while pyruvate conversion to acetyl-SCoA, the initial step in the TCA cycle, takes place in the mitochondrion, a conversion that first requires the transport of the monocarboxylate into this organelle via its inner membrane. Moreover, the existence of mitochondrial LDH is well established, and lactate has been shown to be as good as, if not better than, pyruvate as a substrate for the mitochondrial TCA cycle (Kline et al, 1986;Brandt et al, 1987;Brooks et al, 1999).…”

Section: Role Of Lactate In Adult Brainmentioning

confidence: 99%

“…Interestingly, in their study of mitochondrial preparation from different tissues, Brandt et al (1987) placed a large part of the mitochondrial LDH inside the mitochondria. They distinguished it from cytosolic LDH, characterized by them as LDH5 (see also below), which preferentially adheres to the outer mitochondrial membrane.…”

Section: Role Of Lactate In Adult Brainmentioning

confidence: 99%

“…They distinguished it from cytosolic LDH, characterized by them as LDH5 (see also below), which preferentially adheres to the outer mitochondrial membrane. Of all the different tissues from which these investigators isolated mitochondria, including the heart, kidney, liver lymphocytes and brain, only the latter's mitochondrial preparations were contaminated to a certain extent with three glycolytic enzymes, phosphoglucomutase, phosphoglucose isomerase and 3-phosphoglycerate kinase (Brandt et al, 1987).…”

Section: Role Of Lactate In Adult Brainmentioning

confidence: 99%

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Lactate: The Ultimate Cerebral Oxidative Energy Substrate?

Schurr

2006

J Cereb Blood Flow Metab

268

236

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Research over the past two decades has renewed the interest in lactate, no longer as a useless end product of anaerobic glycolysis in brain (and other tissues), but as an oxidative substrate for energy metabolism. While this topic would be considered blasphemy only three decades ago, much recent evidence indicates that lactate does play a major role in aerobic energy metabolism in the brain, the heart, skeletal muscle, and possibly in any other tissue and organ. Nevertheless, this concept has challenged the old dogma and ignited a fierce debate, especially among neuroscientists, pitting the supporters of glucose as the major oxidative energy substrate against those who support lactate as a possible alternative to glucose under certain conditions. Meanwhile, researchers working on energy metabolism in skeletal muscle have taken great strides toward bridging between these two extreme positions, while avoiding the high decibels of an emotional debate. Employing their findings along with the existing old and new data on cerebral energy metabolism, it is postulated here that lactate is the only major product of cerebral (and other tissues) glycolysis, whether aerobic or anaerobic, neuronal or astrocytic, under rest or during activation. Consequently, this postulate entails that lactate is a major, if not the only, substrate for the mitochondrial tricarboxylic acid cycle. If proven true, this hypothesis could provide better understanding of the biochemistry and physiology of (cerebral) energy metabolism, while holding important implications in the field of neuroimaging. Concomitantly, it could satisfy both 'glucoseniks' and 'lactatians' in the ongoing debate.

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Lactate dehydrogenase in rat mitochondria

Cited by 87 publications

References 20 publications

Physical and Functional Association of Lactate Dehydrogenase (LDH) with Skeletal Muscle Mitochondria

Physical and Functional Association of Lactate Dehydrogenase (LDH) with Skeletal Muscle Mitochondria

Effects of Tissue Protectants on the Kinetics of Lactate Dehydrogenase in Cells

Lactate: The Ultimate Cerebral Oxidative Energy Substrate?

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