Decreased airway responsiveness to histamine in gold salt-treated guinea pigs

The effect of gold salts on airway responsiveness was examined because gold salts appear to be effective in relieving asthmatic symptoms. Seventeen guinea pigs were administered an intramuscular injection of 1 mg of gold sodium thiomalate once a week, and 10 control animals were administered an injection of saline. Three months after the start of the injections, guinea pigs administered gold salt demonstrated significantly decreased airway responsiveness to histamine assessed by respiratory flow patterns and resistance. Some guinea pigs in each group were sacrificed 3 mo after the start of injections, and cyclic nucleotides were measured in the trachea, lung homogenates, and the plasma. No difference was found in the level of adenosine cyclic 3', 5'-monophosphate or guanosine cyclic 3',5' -monophosphate in gold salt-treated animals and control animals. The way in which gold salt alleviates the symptoms of bronchial asthma is discussed on the basis of the results.