TY - JOUR

T1 - Two-week inhalation of budesonide increases muscle Na,K ATPase content but not endurance in response to terbutaline in men

AU - Hostrup, Morten

AU - Jessen, Søren Kaare

AU - Onslev, Johan

AU - Clausen, Torben

AU - Porsbjerg, Celeste Michala

N1 - CURIS 2017 NEXS 155

PY - 2017

Y1 - 2017

N2 - 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.

AB - 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.

U2 - 10.1111/sms.12677

DO - 10.1111/sms.12677

M3 - Journal article

C2 - 27060857

VL - 27

SP - 684

EP - 691

JO - Scandinavian Journal of Medicine & Science in Sports

JF - Scandinavian Journal of Medicine & Science in Sports

SN - 0905-7188

IS - 7

ER -