Two‐week inhalation of budesonide increases muscle Na, K ATPase content but not endurance in response to terbutaline in men. (7th April 2016)

• Record Type: Journal Article
• Authors: Hostrup, M.; Jessen, S.; Onslev, J.; Clausen, T.; Porsbjerg, C.
• Is Part Of: Scandinavian journal of medicine & science in sports. Volume 27:Number 7(2017)
• Page Start: 684
• Page End: 691
• Publication Date: 2016-04-07
• Subjects: Na+, K+ pump -- ATPase -- glucocorticos‐teroids -- ICS -- ion handling -- muscle fatigue -- doping -- physiology -- beta2‐adrenergic; Sports medicine -- Periodicals; Sports -- Physiological aspects -- Periodicals; Sports -- Periodicals; 617.1027
• DOI: 10.1111/sms.12677
• Languages: English
• ISSNs: 0905-7188

Abstract

Abstract : While chronic systemic administration of glucocorticoids increases muscle Na +, K + ATPase content, such effect is unexplored after therapeutic inhalation. We investigated the effect of therapeutic inhalation of the glucocorticoid budesonide on Na +, K + ATPase content of skeletal muscle in men. Ten healthy trained subjects, aged 23 ± 4 years (mean ± 95% CI), participated in the study. Before and after 2 weeks of daily inhalation of budesonide (1.6 mg/day), a biopsy was taken from the vastus lateralis muscle for measurement of Na +, K + ATPase content and blood samples were drawn for determination of plasma budesonide, cortisol, and K + . Subjects' performance during cycling to fatigue at 90% of incremental peak power output (iPPO) was measured in response to 4 mg inhaled terbutaline to maximally stimulate Na +, K + ATPase activity. Plasma concentrations of budesonide rose to 5.0 ± 1.6 nM with the intervention, whereas no changes were observed in plasma cortisol. Muscle Na +, K + ATPase content increased ( P ≤ 0.01) by 46 ± 34 pmol/(g wet wt) (17% increase) with the intervention. Cycling performance at 90% of iPPO did not change ( P = 0.21) with the intervention (203 vs 214 s) in response to terbutaline. The present observations show that therapeutic inhalation of glucocorticoids increases muscle Na +, K + ATPase content, but does not enhance high‐intensity cycling endurance in response to terbutaline.