Mitochondrial content

Mitochondria-associated toxicities, such as pancreatitis, are frequently demonstrated in HlV/HCV-coinfected individuals, and may significantly influence treatment options (de Mendoza and Soriano 2005). Yet, no cell culture or animal models have been developed to predict nucleoside-induced pancreatitis. Nevertheless, an association of HCV replication and mitochondrial DNA depletion in primary human lymphocytes obtained from HIV/HCV-coinfected individuals under concomitant administration of HCV and HIV medications was demonstrated by de Mendoza and coworkers (de Mendoza et al. 2007). They claimed that the use of HCV medication together with certain antiretroviral agents seemed to enhance mitochondrial damage due to a synergistic deleterious interaction between the anti-HCV and anti-HIV drugs. In contrast, an improvement in mitochondrial content with effective... 

Claudio, L., et al. 1990. Increased vesicular transport and decreased mitochondrial content in blood-brain barrier endothelial cells during experimental autoimmune encephalomyelitis. Am J Pathol 135 1157. 

Wodtke, E. (1974). Effects of acclimation temperature on the oxidative metabolism of the eel (Anguilla anguilla). 1. Liver and red muscle. Changes in the mitochondrial content and in the oxidative capacity of isolated coupled mitochondria. Journal of Comparative Physiology 91,309-332. 

In humans, the mitochondrial content of slow-twitch red fibers is typically greater than that of the fast-twitch red fibers... 

Similarly, measurements of blood flows to sections of muscle, which are primarily composed of a single fiber type, exhibit large differences consistent with the expected demands of oxygen supply based on mitochondrial content (32,33). Thus, mammalian skeletal muscle is typically comprised of three biochemically and functionally distinct fiber types slow-twitch red, fast-twitch red and fast-twitch white. These fiber types are also commonly referred to as Type I, Type Ila, and Type 11b, respectively (7 ). 

Figure 1. The predicted consequences of one week of detraining and the time of retraining required to recover the full Increase In cytochrome c content (an index of mitochondrial content) In the working muscle. Note that In one week of Inactivity (approx. 1 half-life), nearly 50% of the training effect is lost. Similarly, each week of retraining recovers approx. 50% of the way toward the full training effect. Since the process exhibits first-order kinetics. It takes longer to recover fully. "Reproduced with permission from Ref. 56. Copyright 1977, New York Academy of Sciences. "...

When the resting parietal cell is stimulated by acid secretagogues, the tubulovesicles are transformed into the secretory canaliculus. The parietal cell has the largest mitochondrial content of any mammalian cell (—34% of cell volume) and the ATP generated by this is mainly used for acid secretion. Hydrolysis of ATP results in a conformational change in the protein that mediates the electroneutral exchange of intracellular and extracellular K+. The pump is activated only when it is associated with a potassium chloride pathway in the canalicular membrane (Fig. 3.6). This allows potassium chloride efflux into the extra-cytoplasmic space and thus results in the secretion of HCl at the expense of ATP... 

Decreased Complex I activity in fatty liver mitochondria isolated from rats fed with a choline-deficient diet to model in animals nonalcoholic fatty liver disease could also be completely restored to the level of control livers by exogenously added CL (Petrosillo et al., 2007). Under conditions of a choline-deficient diet the mitochondrial content of CL decreased due to reactive oxygen species-induced CL oxidation. Although no high-resolution crystal structure of the entire Complex I is available, these findings strongly suggest the presence of functionally important CL molecules in the complex. 

Su, X., Dowhan, W. 2006. Translational regulation of nuclear gene COX4 expression by mitochondrial content of phosphatidylglycerol and cardiolipin in Saccharomyces cerevisiae. Mol. Cell. Biol. 26 743-753. Dowhan, W. 1997. Molecular basis for membrane phospholipid diversity why are there so many phospholipids. Annu. Rev. Biochem. 66 199-232. 

The heart, with its huge mitochondrial content and oxidative capacity, is able to use lactate released from other tissues as a fuel. During an exercise such as bicycle riding, lactate released into the blood from skeletal muscles in the leg might be used by resting skeletal muscles in the arm. In the brain, glial cells and astrocytes produce lactate, which is used by neurons or released into the blood. 

S.L. Gibson, M.L. Nguyen, J.J. Havens, A. Barbarin, R. Hilf (1999). Relationship of delta-aminolevulinic acid-induced protoporphyrin IX levels to mitochondrial content in neoplastic cells in vitro. Biochem. Biophys. Res. Commun., 265, 315-321. 

MHC2a> values for MHC content per half-sarcomere are lower than expected for the corresponding CSA, due to their relatively higher mitochondrial content compared to fibers expressing MHC2X and/or MHC2b-... 

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