The qualitative evaluation of airway responses to immunologic and pharmacologic stimuli in rhesus monkeys

This report describes the current status of a colony of rhesus monkeys composed of a group of animals with consistent asthmatic responses to Ascaris antigen challenge, a variable group and a negative group. The cumulative experience with the consistent group of 5 animals totals 144 months of observation with 86 positive respiratory responses to 86 aerosol challenges. Further studies compare rhesus airway responses to Ascaris antigen, anti-IgE, histamine, prostaglandin (PG)F2alpha, carbocholine, and physostigmine. We report that two abnormalities of pulmonary function which occur as a result of aerosol challenge, an increase in breathing frequency (f) and pulmonary resistance (PR), differ in degree of abnormality and time of onset following challenge with different agonists. These results indicate that the f and PR changes in response to these agonists are controlled by different physiologic mechanisms in rhesus monkeys. We suggest that the f changes may occur as a result of reflex afferent vagal stimulation and PR changes as a result of direct effect on smooth muscle receptors. The effect of histamine and PGF2alpha on the airway of rhesus monkeys more closely simulates the airway response to immunologic stimuli than does the effect of cholinergic type agonists.