While the use of oral beta (2)-agonists by athletes is prohibited because of their
anabolic effects, some inhaled beta (2)-agonists can be used in accordance with the World Anti-Doping Agency regulations. We examined the dose disparity between the bronchodilating effect and
anabolic effect of inhaled
procaterol, a selective beta (2)-agonist, to determine if the
drug might be effective for athletes with
asthma. Intact rats were given nebulized
procaterol at 0.001, 0.01, 0.1 and 1 mg/mL by inhalation, and its inhibitory effect on
carbachol-induced bronchoconstriction was evaluated. Castrated rats were given nebulized
procaterol at 0.03, 0.1, 0.3 and 1 mg/mL by inhalation 3 times a day for 14 days, and anabolic markers (
body weight gain, weight of the levator ani muscle and gastrocnemius muscle) were measured. At 0.01 mg/mL and higher,
procaterol dose-dependently inhibited
carbachol-induced bronchoconstriction with a significant effect. At doses of up to 0.3 mg/mL, there were no signs indicating an
anabolic effect of
procaterol. At 1 mg/mL, however, a slight but statistically significant increase in the weight of the levator ani muscle was observed with no significant changes in other anabolic markers. It was suggested that inhaled
procaterol might be useful for athletes with
asthma because of the big dose disparity between its bronchodilating effect and
anabolic effect in rats.