The Influence of Sex on Fiber-Specific Morphological and Metabolic Characteristics of Human Skeletal Muscle
Year: 2023
Type: dissertation
Study design: Observational Study
Abstract: We evaluated the influence of sex on whole muscle and fiber-specific indices of mitochondrial content, capillarization, and muscle morphology of untrained adults. Resting muscle biopsy samples obtained from age- and body mass index-matched females (n=14) and males (n=13) were analyzed via immunofluorescence and Western Blotting. Type IIa (p=0.003) and IIx (p=0.002) fibers, but not type I fibers (p=0.24), were smaller in females compared to males. Compared to males, females had a lower proportionate area of type IIa fibers (p=0.02) and a greater proportionate area of type I fibers (p=0.01). There were no differences between sexes in most whole muscle or fiber-specific indices of capillary and mitochondrial content; however, increased capillary density in type I vs. type II fibers was observed in males (p=9.37x10-5) but not females (p=0.76). In conclusion, we demonstrate that type I and type II muscle fiber morphology, but not oxidative capacity, differs between untrained males and females.
Source: TSpace (University of Toronto)
Author: Bailleul, Celine
Institution: University of Toronto
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7133097637