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Updated: May 28, 2026
Subcutaneous Neurotrophin 4 Infusion Using Osmotic Pumps or Direct Muscular Injection Enhances Aging Rat Laryngeal Muscles
Published on: June 13, 2017
Structural and functional properties of an upper airway dilator muscle in aged obese male rats
J Richard Skelly1, Ruth A O'Connell, James F X Jones
1UCD School of Medicine and Medical Science, Health Sciences Centre, University College Dublin, Dublin, Ireland.
Background:
Age, obesity and male sex are risk factors for the development of obstructive sleep apnoea syndrome.
Objective:
We examined structural and functional properties of the sternohyoid muscle in young lean and aged obese male rats. We hypothesized that the aged muscle would be vulnerable to oxidative stress (hypoxia).
Methods:
Isometric contractile and endurance properties of the sternohyoid muscle were assessed in vitro with or without the superoxide scavenger Tempol (10 mM). Muscle fibre size and density were determined by myosin heavy chain immunofluorescence. Succinate dehydrogenase (SDH) and glycerol-3- phosphate dehydrogenase (GPDH) enzyme activities were determined.
Results:
Fibre hypertrophy, increased fast twitch (type 2X) fibre density, decreased SDH activity and increased GPDH activity, together with increased force and fatigue, were observed in aged obese muscles compared to young lean muscles. Tempol treatment increased strength and sensitivity to stimulation. Hypoxic depression of force was ameliorated by antioxidant treatment with equivalent effects in young lean and aged obese muscle.
Conclusions:
We conclude that the rat sternohyoid exhibits indefinite growth and is protected from oxidative stress as the animal ages.
