Mitochondrial functional impairment with aging is exaggerated in isolated mitochondria compared to permeabilized myofibers.
نویسندگان
چکیده
Mitochondria regulate cellular bioenergetics and apoptosis and have been implicated in aging. However, it remains unclear whether age-related loss of muscle mass, known as sarcopenia, is associated with abnormal mitochondrial function. Two technically different approaches have mainly been used to measure mitochondrial function: isolated mitochondria and permeabilized myofiber bundles, but the reliability of these measures in the context of sarcopenia has not been systematically assessed before. A key difference between these approaches is that contrary to isolated mitochondria, permeabilized bundles contain the totality of fiber mitochondria where normal mitochondrial morphology and intracellular interactions are preserved. Using the gastrocnemius muscle from young adult and senescent rats, we show marked effects of aging on three primary indices of mitochondrial function (respiration, H(2) O(2) emission, sensitivity of permeability transition pore to Ca(2+) ) when measured in isolated mitochondria, but to a much lesser degree when measured in permeabilized bundles. Our results clearly demonstrate that mitochondrial isolation procedures typically employed to study aged muscles expose functional impairments not seen in situ. We conclude that aging is associated with more modest changes in mitochondrial function in sarcopenic muscle than suggested previously from isolated organelle studies.
منابع مشابه
Mitochondrial Structure and Function Are Disrupted by Standard Isolation Methods
Mitochondria regulate critical components of cellular function via ATP production, reactive oxygen species production, Ca(2+) handling and apoptotic signaling. Two classical methods exist to study mitochondrial function of skeletal muscles: isolated mitochondria and permeabilized myofibers. Whereas mitochondrial isolation removes a portion of the mitochondria from their cellular environment, my...
متن کاملFunctional Imaging of Mitochondria in Saponin-permeabilized Mice Muscle Fibers
Confocal laser-scanning and digital fluorescence imaging microscopy were used to quantify the mitochondrial autofluorescence changes of NAD(P)H and flavoproteins in unfixed saponin-permeabilized myofibers from mice quadriceps muscle tissue. Addition of mitochondrial substrates, ADP, or cyanide led to redox state changes of the mitochondrial NAD system. These changes were detected by ratio imagi...
متن کاملToxicity of Arsenic (III) on Isolated Liver Mitochondria: A New Mechanistic Approach
Arsenic exposure mainly through food and water has been shown to be associated with increased incidence of numerous cancers and non-cancer harmful health. It is also used in cancer chemotherapy and treatment of several cancer types due to its apoptogenic effects in the various cancer and normal cell lines. We have already reported that liver is the storage site and important target organ in As ...
متن کاملToxicity of Arsenic (III) on Isolated Liver Mitochondria: A New Mechanistic Approach
Arsenic exposure mainly through food and water has been shown to be associated with increased incidence of numerous cancers and non-cancer harmful health. It is also used in cancer chemotherapy and treatment of several cancer types due to its apoptogenic effects in the various cancer and normal cell lines. We have already reported that liver is the storage site and important target organ in As ...
متن کاملA Search for Mitochondrial Damage in Alzheimer’s Disease Using Isolated Rat Brain Mitochondria
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that affects regions of the brain that control cognition, memory, language, speech and awareness to one’s physical surroundings. The pathological initiation and progression of AD is highly complex and its prevalence is on the rise. In his study, Alzheimer's disease was induced with single injection of amyloid-β (Aβ) peptides (...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Aging cell
دوره 9 6 شماره
صفحات -
تاریخ انتشار 2010