Abstract:Dingchuanning has been found to increase merkedly the perfusion of isolated lung of guinea-pig. It may I roduce a relaxing effect on the smooth muscles of the isolated trachea, bronchus and lung strips of guinea-pigs, as well as a prominent protective effect on the bronchial asthma induced by inhalation of bronchoconstrictors in conscious guinea-pigs. It also has significant expectorant and antianaphylactic effcets and helps to inhibit markedly the SRS-A release from lung tissues and to counteract directly the activity of SRS-A.