Respiratory responses to Ascaris antigen in rhesus and cynomolgus monkeys

Responses to Ascaris antigen were evaluated in rhesus and cynomolgus monkeys. Of 19 cynomolgus monkeys tested, 15 were found to have cutaneous reactivity to Ascaris: 13 of these responded to Ascaris aerosols with changes in respiratory function including an increase in respiration rate, decrease in tidal volume and peak expiratory flow rate, decrease in dynamic compliance, and an increase in resistance. Four of the six rhesus monkeys studied with cutaneous reactivity to Ascaris responded to Ascaris aerosols: the changes in respiratory function observed after the Ascaris challenge in these monkeys were similar to those observed in the cynomolgus monkeys. Responses to repetitive Ascaris challenges were obtained in monkeys of both species with a recovery period of 30 to 60 min between challenges. In monkeys of both species that reacted to Ascaris aerosols, blood pressure was elevated transiently; changes in heart rate were variable. Changes in cardiovascular measurements were not observed in monkeys that did not respond to Ascaris aerosols. Thus, it appears that the cynomolgus monkey responds to an aerosol Ascaris challenge in a manner similar to the rhesus monkey and is an additional suitable model for the study of allergic respiratory responses.