Date of Award
Doctor of Physical Therapy (DPT)
Background: Ageing is associated with sarcopenia and a change of composition in muscle fibers. Ames dwarf mice have been found to have a decreased susceptibility to the deleterious effects of the ageing process, when compared to a normal mouse counterpart. This study looks at the muscle composition of the Ames dwarf mouse compared to the normal mouse by analyzing two muscles, ELD and Sol.
Methods: Researchers harvested hind limb muscles from Ames dwarf mice and normal mice. The fours muscles were EDL, Sol, Gastrocnemius/Plantaris, and TA. EDL and Sol were sliced and stained with fast and slow twitch and H&E stains. Muscle cell diameter and fast and slow twitch percentage were measured through images obtained.
Results: The following results were obtained using SPSS, version 18. For EDL, no significant difference was found between age of mice. A sig diff was found when comparing the total means of the type of mice. For Soleus, a significant interaction was found (p<.001) between mouse types and age. A significant difference in mouse types(dwarf and normal) was found at 3 months and also 12 months. A significant difference was found between normal mice at 3 and 12 months, while no significant difference was found between dwarf mice at 3 and 12 months. Percentages of fast and slow twitch muscle fibers were documented. No statistical analysis was used to determine significance.
Discussion: These results suggest that there are physiological differences between normal and Ames dwarf mice. Researchers expected to find a significant decrease is muscle cell diameter as the mouse aged; however, results showed that the muscle cell diameter actually increased with age. This may be due to the mouse not reaching full maturity during the age groups used in this study. The Further research is needed to substantiate the results of this study. Researchers suggest analyzing age groups of 24 months.
Dahlheimer, Kristine, "FIBER TYPE AND CROSS-SECTIONAL AREA CHARACTERISTICS IN HINDLIMB MUSCLES OF THE LONG-LIVED AMES DWARF MOUSE" (2012). Physical Therapy Scholarly Projects. 626.