Abstract
Gender differences in fatigue manifest as females being more prone to feel exhaustion and having lower muscle endurance. However, the mechanisms of these effects remain unclear. We investigated whether orosomucoid, an endogenous anti-fatigue protein that enhances muscle endurance, is involved in this regulation. Female rats exhibited lower muscle endurance, and this gender difference disappeared in orosomucoid-1-deficient mice. Female rats also exhibited weaker orosomucoid induction in serum, liver and muscle in response to fatigue compared with male rats. Ovariectomy elevated orosomucoid levels and increased swimming time, and estrogen replenishment reversed these effects. Exogenous estrogen treatment in male and female mice produced opposite effects. Estrogen decreased orosomucoid expression and its promoter activity in C2C12 muscle and Chang liver cells in vitro, and estrogen receptor or p38 mitogen-activated protein kinase blockade abolished this effect. Therefore, estrogen negatively regulates orosomucoid expression that is responsible for the weaker muscle endurance in females.
Highlights
Fatigue generally manifests as a reversible decline in performance by affected individuals,[1] and it is divided into central fatigue and physical fatigue
Females exhibited lower muscle endurance than males in vivo and in vitro We investigated whether gender difference in fatigue and muscle endurance existed in rodent fatigue models
It is well known that weight-loaded forced-swimming and treadmillrunning models are similar to physical fatigue, and the sleepdeprivation model is generally used in the study of chronic fatigue syndrome patients.[32]
Summary
Fatigue generally manifests as a reversible decline in performance by affected individuals,[1] and it is divided into central fatigue and physical fatigue. Lower endurance test scores were found for women than for men in healthy people and in patients, especially in athletes.[5,6,13,14,15,16] These studies are consistent with the fact that female sports records are not as good as those of males, and female work endurance is generally shorter than that of males. These gender differences likely protect females from being overworked and suggest that some hormonal factors, estrogen, are involved in this phenomenon. No direct evidence or an underlying mechanism has been clearly established
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
