Effect of Thyroxine was studied in histamine induced bronchospasm in guinea pigs. Chronic treatment with the drug significantly protected against experimental bronchospasm. Thyroxine also potentiated salbutamol evoked bronchodilation in this experimental model. Up-regulation of beta-2 adrenoceptors in bronchial smooth muscle may be the probable mechanism of action of thyroxine.
Albuterol Animals