What question did this study set out to answer?

To determine the metabolic changes induced by increased mechanical workload in isolated rat hearts during ketone body production or uptake and evaluate methods for measuring mitochondrial free NAD+/NADH ratios.

June 1, 1975Biochemical JournalOpen Access

Effects of increased mechanical work by isolated perfused rat heart during production or uptake of ketone bodies. Assessment of mitochondrial oxidized to reduced free nicotinamide-adenine dinucleotide ratios and oxaloacetate concentrations

View Full Paper

Ask AI

Bookmark

Authors

LOLionel H. OpieGeneral Cardiology POP OwenPadjadjaran University

Discussion

Member takes

Implication

Ex vivo comparative study demonstrates altered substrate flux and energy depletion during increased work in isolated rat hearts, indicating limitations in estimating mitochondrial redox states.

Key Points

To determine the metabolic changes induced by increased mechanical workload in isolated rat hearts during ketone body production or uptake and evaluate methods for measuring mitochondrial free NAD+/NADH ratios.
Compared isolated pumping rat hearts (atrial-filling technique) with non-pumping rat hearts (Langendorff aortic perfusion) supplied with 11 mM glucose and 0.6 mM palmitate bound to albumin.
Measured tissue metabolite levels, substrate utilization, and ketone body ratios under baseline conditions and following the addition of 4 mM ketone bodies.
Increased cardiac workload resulted in a threefold increase in oxygen and glucose uptake, whereas free fatty acid uptake remained unchanged.
Work-performing hearts showed significant accumulation of alpha-oxoglutarate, ammonium, malate, lactate, pyruvate, and inorganic phosphate, alongside depletion of ATP, phosphocreatine, and citrate.
Ketone bodies were produced with a beta-hydroxybutyrate to acetoacetate ratio of approximately 3:1 in both groups, but low cardiac activity of glutamate and beta-hydroxybutyrate dehydrogenases invalidates direct application of liver-based mitochondrial NAD+/NADH calculations to the heart.

Cite This Study

Opie et al. (1975) studied this question.

synapsesocial.com/papers/6a9affb0af516d3b8a7c5031 https://doi.org/10.1042/bj1480403

View Full Paper

Ask AI

Bookmark

Implication

Ex vivo comparative study demonstrates altered substrate flux and energy depletion during increased work in isolated rat hearts, indicating limitations in estimating mitochondrial redox states.

Effects of increased mechanical work by isolated perfused rat heart during production or uptake of ketone bodies. Assessment of mitochondrial oxidized to reduced free nicotinamide-adenine dinucleotide ratios and oxaloacetate concentrations

Discussion

Member takes

Implication

Key Points

Cite This Study

Effects of increased mechanical work by isolated perfused rat heart during production or uptake of ketone bodies. Assessment of mitochondrial oxidized to reduced free nicotinamide-adenine dinucleotide ratios and oxaloacetate concentrations

Discussion

Member takes

Implication

Key Points

Cite This Study

Also Consider

Also Consider