Chronic hypobaric hypoxia increases isolated rat fast-twitch and slow-twitch limb muscle force and fatigue

Title:

Chronic hypobaric hypoxia increases isolated rat fast-twitch and slow-twitch limb muscle force and fatigue

Creator:

El-Khoury, R., Bradford, A., and O´Halloran, K. D.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:69046f4a-a61f-451b-a8be-b1cfa61821a0
uuid:69046f4a-a61f-451b-a8be-b1cfa61821a0

Subject:

Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, hypoxia, skeletal muscle, fatigue, 14, and 612

Type:

article, články, model:article, and TEXT

Description:

Chronic hypoxia alters respiratory muscle force and fatigue, effects that could be attributed to hypoxia and/or increased activation due to hyperventilation. We hypothesized that chronic hypoxia is associated with phenotypic change in non-respiratory muscles and therefore we tested the hypothesis that chronic hypobaric hypoxia increases limb muscle force and fatigue. Adult male Wistar rats were exposed to normoxia or hypobaric hypoxia (PB=450 mm Hg) for 6 weeks. At the end of the treatment period, soleus (SOL) and extensor digitorum longus (EDL) muscles were removed under pentobarbitone anaesthesia and strips were mounted for isometric force determination in Krebs solution in standard water-jacketed organ baths at 25 °C. Isometric twitch and tetanic force, contractile kinetics, forcefrequency relationship and fatigue characteristics were determined in response to electrical field stimulation. Chronic hypoxia increased specific force in SOL and EDL compared to age-matched normoxic controls. Furthermore, chronic hypoxia decreased endurance in both limb muscles. We conclude that hypoxia elicits functional plasticity in limb muscles perhaps due to oxidative stress. Our results may have implications for respiratory disorders that are characterized by prolonged hypoxia such as chronic obstructive pulmonary disease (COPD)., R. El-Khoury, A. Bradford, K. D. O´Halloran., and Obsahuje seznam literatury

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2012 Volume:61 | Number:2

Harvested from:

CDK

Metadata only:

false