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Malondialdehyde content and circadian variations in brain, kidney, liver, and plasma of mice
Mamane Sani1, Néziha Ghanem-Boughanmi, Wafa Gadacha
1Laboratoire de Biosurveillance de l'Environnement, Faculté des Sciences de Bizerte, 7021 Zarzouna, Tunisia.
Abstract:
In aerobic organisms, the use of oxygen (O(2)) to produce energy is associated with the production of Reactive Oxygen Species (ROS), which reacts with biological molecules to produce oxidized metabolites such as malondialdehyde (MDA). This experiment focused on male Swiss mice 12 weeks of age synchronized for 3 weeks by the 12 h light (rest)/12 h dark (activity) span. Different and comparable groups of animals (n=10) were sacrificed at six different circadian stages: 1, 5, 9, 13, 17, and 21 h after light onset (HALO). The 24 h mean MDA level varied among organs of mice in non-stress conditions and was comparable in brain and liver but lower than in kidney. As the MDA 24 h status constitutes only a part of ROS damages in sites differing by their oxygen use, lipid composition, and detoxification capacity, the temporal patterns of their MDA content were comparatively studied in relationship to the animal rest-activity cycle. The results revealed significant circadian rhythms with the peak time located during the rest span (approximately =5 HALO) for both brain and liver, but during the activity span for the kidney ( approximately =21 HALO) and plasma (approximately =13 HALO). This chronobiological study showed that under physiological conditions, lipid peroxidation depends on several factors. The MDA peak/trough might be used as a tool to detect moments of high/low sensitivity of tissues to ROS attack in rodents.
Insights
Reactive Oxygen Species (ROS) cause oxidative stress, measured by malondialdehyde (MDA). This study reveals circadian rhythms in MDA levels across mouse organs, indicating varying tissue sensitivity to ROS attack.
Area of Science:
- Chronobiology
- Biochemistry
- Physiology
Background:
- Aerobic metabolism generates Reactive Oxygen Species (ROS), leading to oxidative damage.
- Malondialdehyde (MDA) is a key biomarker of lipid peroxidation and ROS-induced cellular damage.
- Understanding organ-specific ROS production and damage is crucial for physiological health.
Purpose of the Study:
- To investigate the circadian patterns of malondialdehyde (MDA) levels in different organs of male Swiss mice.
- To correlate MDA temporal variations with the animal's rest-activity cycle.
- To assess the potential of MDA peak/trough times as indicators of tissue susceptibility to ROS.
Main Methods:
- Male Swiss mice were synchronized to a 12h light/12h dark cycle for 3 weeks.
- Groups of mice (n=10) were sacrificed at six time points across a 24-hour period (1, 5, 9, 13, 17, 21 hours after light onset).
- MDA levels were quantified in brain, liver, kidney, and plasma to analyze temporal variations and circadian rhythms.
Main Results:
- Significant circadian rhythms in MDA levels were observed across different organs.
- Brain and liver exhibited peak MDA levels during the rest phase (approx. 5 HALO).
- Kidney and plasma showed peak MDA levels during the activity phase (approx. 21 HALO and 13 HALO, respectively).
Conclusions:
- Lipid peroxidation, indicated by MDA levels, exhibits significant organ-specific circadian variation under physiological conditions.
- These temporal patterns are influenced by the rest-activity cycle and organ-specific factors.
- MDA peak and trough times can serve as valuable indicators for assessing tissue sensitivity to ROS attack in rodents.