The present study examines the effect of salbutamol, a beta 2-adrenorecepto
r agonist, on blood ammonia levels during an incremental cycle exercise tes
t in healthy non-asthmatic subjects. Blood ammonia levels were lower after
inhalation of 400 meg of salbutamol than after placebo during submaximal ex
ercise: 33 +/- 2 mu mol.l(-1) vs 48 +/- 9 mu mol.l(-1) at 220 W and 39 +/-
2 mu mol.l(-1) vs 50 +/- 4 mu mol.l(-1) at 260 W. At peak exercise there we
re no significant differences. The results suggest that beta 2-adrenorecept
ors are involved in the regulation of blood ammonia during exercise.