Rhesus monkey airway responses to substance P

The tachykinin, substance P (SP), was used as a model to study airway and cutaneous responses in a group of normal rhesus monkeys or animals with IgE-mediated cutaneous reactions to Ascaris antigen (AA) alone or animals with both IgE-mediated cutaneous and airway responses to AA. Aerosolized SP (10 mg/ml) resulted in airway responses qualitatively similar in duration and pulmonary function abnormalities to AA. These SP airway responses were most closely associated with the presence of IgE antibody to AA and were not increased in animals with airway reactivity to AA. A dose response to aerosolized SP can be established. An enkephalinase inhibitor, thiorphan, did not potentiate SP airway responses but appeared to potentiate SP cutaneous responses in some animals. SP cutaneous reactions could be demonstrated and did not correlate with the IgE-mediated cutaneous dilution titers to AA.