Desensitization to experimental asthma with 48/80

The mast cell disintegrating histamine releaser, compound 48/80, given daily for 5 days by aerosol to guinea pigs produced relative resistance to 48/80 induced asthma, but not to histamine induced asthma. After 3 days of rest, sensitivity to the respiratory effects of 48/80 returned to baseline level. It was thought that the effects observed were due to depletion of pulmonary mast cells or their asthma mediators and regeneration after a period of rest.