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Two‐week inhalation of budesonide increases muscle Na,K ATPase content but not endurance in response to terbutaline in men
Author(s) -
Hostrup M.,
Jessen S.,
Onslev J.,
Clausen T.,
Porsbjerg C.
Publication year - 2017
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12677
Subject(s) - inhalation , budesonide , terbutaline , medicine , endocrinology , chemistry , glucocorticoid , atpase , anesthesia , asthma , biochemistry , enzyme
While chronic systemic administration of glucocorticoids increases muscle Na + ,K + ATP ase content, such effect is unexplored after therapeutic inhalation. We investigated the effect of therapeutic inhalation of the glucocorticoid budesonide on Na + ,K + ATP ase 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 + ATP ase 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 + ATP ase 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 + ATP ase 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 + ATP ase content, but does not enhance high‐intensity cycling endurance in response to terbutaline.