Serna 2020 J Bioenerg Biomembr
|Serna JDC, Caldeira da Silva CC, Kowaltowski AJ (2020) Functional changes induced by caloric restriction in cardiac and skeletal muscle mitochondria. J Bioenerg Biomembr [Epub ahead of print].|
Abstract: Caloric restriction (CR) is widely known to increase life span and resistance to different types of injuries in several organisms. We have previously shown that mitochondria from livers or brains of CR animals exhibit higher calcium uptake rates and lower sensitivity to calcium-induced mitochondrial permeability transition (mPT), an event related to the resilient phenotype exhibited by these organs. Given the importance of calcium in metabolic control and cell homeostasis, we aimed here to uncover possible changes in mitochondrial calcium handling, redox balance and bioenergetics in cardiac and skeletal muscle mitochondria in response to six months of CR. Unexpectedly, we found that CR does not alter the susceptibility to mPT in muscle (cardiac or skeletal), nor calcium uptake rates. Despite the lack in changes in calcium transport properties, CR consistently decreased respiration in the presence of ATP synthesis in heart and soleus muscle. In heart, such changes were accompanied by a decrease in respiration in the absence of ATP synthesis, lower maximal respiratory rates and a reduced rate of hydrogen peroxide release. Hydrogen peroxide release was unaltered by CR in skeletal muscle. No changes were observed in inner membrane potentials and respiratory control ratios. Together, these results highlight the tissue-specific bioenergetic and ion transport effects induced by CR, demonstrating that resilience against calcium-induced mPT is not present in all tissues.
• Keywords: Bioenergetics, Caloric Restriction, Heart, Mitochondrial Permeability Transition, Reactive Oxygen Species, Soleus Muscle • Bioblast editor: Plangger M • O2k-Network Lab: BR Sao Paulo Kowaltowski AJ
Labels: MiParea: Respiration, Exercise physiology;nutrition;life style Pathology: Aging;senescence Stress:Permeability transition Organism: Rat Tissue;cell: Heart, Skeletal muscle Preparation: Isolated mitochondria
Coupling state: LEAK, OXPHOS Pathway: S HRR: Oxygraph-2k