Study of Age-Dependent Structural and Functional Changes of Mitochondria in Skeletal Muscles and Heart of Naked Mole Rats (Heterocephalus glaber)

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S. Holtze^1*, C. M. Eldarov², V. B. Vays², I. M. Vangeli², M. Yu. Vysokikh^2*, L. E. Bakeeva^2*, V. P. Skulachev², and T. B. Hildebrandt¹

¹Leibniz Institute for Zoo and Wildlife Research, Department of Reproduction Management, 10315 Berlin, Germany; E-mail: holtze@izw-berlin.de

²Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, 119991 Moscow, Russia; E-mail: bakeeva@belozersky.msu.rui, mike@genebee.msu.ru

^* To whom correspondence should be addressed.

Received July 8, 2016

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Morphometric analysis of mitochondria in skeletal muscles and heart of 6- and 60-month-old naked mole rats (Heterocephalus glaber) revealed a significant age-dependent increase in the total area of mitochondrial cross-sections in studied muscle fibers. For 6- and 60-month-old animals, these values were 4.8 ± 0.4 and 12.7 ± 1.8%, respectively. This effect is mainly based on an increase in the number of mitochondria. In 6-month-old naked mole rats, there were 0.23 ± 0.02 mitochondrial cross-sections per µm² of muscle fiber, while in 60-month-old animals this value was 0.47 ± 0.03. The average area of a single mitochondrial cross-section also increased with age in skeletal muscles – from 0.21 ± 0.01 to 0.29 ± 0.03 µm². Thus, naked mole rats show a drastic enlargement of the mitochondrial apparatus in skeletal muscles with age due to an increase in the number of mitochondria and their size. They possess a neotenic type of chondriome accompanied by specific features of mitochondrial functioning in the state of oxidative phosphorylation and a significant decrease in the level of matrix adenine nucleotides.

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KEY WORDS: naked mole rat, morphometry, respiration, aging, ultrastructure, mitochondria, neoteny

DOI: 10.1134/S000629791612004X

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