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Updated: Sep 28, 2025
Assessment of Cardiac Function and Energetics in Isolated Mouse Hearts Using 31P NMR Spectroscopy
Published on: August 31, 2010
Effects of caloric overload before caloric restriction in the murine heart
Martin Maldonado1, Jianying Chen1, Huiqin Duan1
1Reproductive Medicine and Genetics, Chengdu Jinjiang Hospital for Maternal and Child Health Care, Chengdu 610066, China.
Insights
Caloric restriction (CR) benefits cardiac aging, but a high-calorie diet (HCD) background diminishes its effects on heart tissue. Understanding these dietary influences is key for developing strategies to promote heart health and longevity.
Area of Science:
- Cardiovascular Research
- Aging Biology
- Nutritional Science
Background:
- Caloric restriction (CR) offers numerous cardiovascular benefits, yet its efficacy may be influenced by prior dietary habits.
- The impact of a high-calorie diet (HCD) background on CR's mechanisms in whole heart tissue (WHT) remains largely uninvestigated in murine models.
Purpose of the Study:
- To investigate how a HCD background affects the mechanisms of CR in WHT.
- To compare cardiac energetics, stem cell markers, and energy-sensing networks in mice with different dietary histories undergoing CR.
Main Methods:
- Transthoracic echocardiography was performed on CR-treated mice with varied dietary backgrounds.
- Whole heart tissue (WHT) analysis included cardiac energetics, telomerase activity, adiponectin, stem cell markers, and energy-sensing network expression.
Main Results:
- Mice on a balanced diet before CR showed improved cardiac remodeling, ejection fraction (EF), fractional shortening (FS), and mitochondrial function (OXPHOS, CKMT2).
- Mice with an HCD background before CR exhibited moderate cardiac changes with reduced EF/FS but improved OXPHOS complex IV and CKMT2 activity.
- Differences in cardiac remodeling and mitochondrial energetics correlated with altered expression of mitochondrial biogenesis markers and disrupted eNOS, AMPK, PGC-1α, and mTOR pathways.
Conclusions:
- A prior HCD background can modulate the beneficial effects of CR on cardiac structure and mitochondrial energetics.
- Disruptions in key regulatory networks (e.g., AMPK-PGC-1α-mTOR) may underlie the diminished CR benefits.
- Further research into the impact of dietary history on CR efficacy is crucial for developing targeted health and longevity strategies.
Abstract:
The beneficial effects of caloric restriction (CR) against cardiac aging and for prevention of cardiovascular diseases are numerous. However, to our knowledge, there is no scientific evidence about how a high-calorie diet (HCD) background influences the mechanisms underlying CR in whole heart tissue (WHT) in experimental murine models. In the current study, CR-treated mice with different alimentary backgrounds were subjected to transthoracic echocardiographic measurements. WHT was then analyzed to determine cardiac energetics, telomerase activity, the expression of energy-sensing networks, tissue-specific adiponectin, and cardiac precursor/cardiac stem cell markers. Animals with a balanced diet consumption before CR presented marked cardiac remodeling with improved ejection fraction (EF) and fractional shortening (FS), enhanced OXPHOS complex I, III, and IV, and CKMT2 enzymatic activity. Mice fed an HCD before CR presented moderate changes in cardiac geometry with diminished EF and FS values, but improved OXPHOS complex IV and CKMT2 activity. Differences in cardiac remodeling, left ventricular systolic/diastolic performance, and mitochondrial energetics, found in the CR-treated mice with contrasting alimentary backgrounds, were corroborated by inconsistencies in the expression of mitochondrial-biogenesis-related markers and associated regulatory networks. In particular, disruption of eNOS and AMPK -PGC-1α-mTOR-related axes. The impact of a past habit of caloric overload on the effects of CR in the WHT is a scarcely explored subject that requires deeper study in combination with analyses of other tissues and organs at higher levels of organization within the organ system. Such research will eventually lead to the development of preventative and therapeutic strategies to promote health and longevity.
