Antiallergic bronchodilator compounds

There are other compounds in the literature which seem to have a potentially useful blend of bronchodilator and antiallergy action. Compound IX, having a cromolyn-type structure, is effective in the passive cutaneous anaphylaxis test in rats as well as in the histamine aerosol test in guinea pigs (22). It has less cardiovascular effects than theophylline but causes some CNS stimulation. Compound X is a recent compound which in animals appears to be more potent than theophylline in its bronchodilator/antiallergic actions and also appears to have greater broncho-selectivity (23, 24). 

Research in respiratory disease at Mead Johnson has centered on heterocyclic molecules having a mixture of bronchodilator and antiallergic actions. One of these, an imidazopurinone (compound XI), recently emerged with particularly interesting pharmacologic features. Illustrated in Figure 6 are dose-response curves for intraduodenally administered compound XI in three appropriate tests in rats. 

Although the discovery of these antiallergic compounds was a development of a study of the antispasmodic and especially the bronchodilator action of khellin, these chromones do not have a direct effect on smooth muscle and their therapeutic mode of action is of a different kind from that of khellin. They do not usually possess antihistaminic activity neither do they antagonise the actions of other spasmogens which may be associated... 

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