The activity of aerosolized and intracutaneous synthetic platelet activating factor (AGEPC) in rhesus monkeys with IgE-mediated airway responses and normal monkeys.

AGEPC, a synthetic platelet activating factor was studied by aerosol or cutaneous challenge in rhesus monkeys with or without IgE-mediated airway responses. The AGEPC qualitatively reproduced an antigen type of airway response. The monkeys with airway reactivity to antigen were reactive to lower concentrations of AGEPC than normal monkeys. Although very low concentrations of AGEPC produced cutaneous reactions, no cutaneous hyperreactivity was present in antigen-reactive animals. The threshold concentrations of AGEPC producing an airway reaction were 1/600 and 1/20,000 those of leukotriene D4 and histamine, respectively. These results could be consistent with AGEPC as a highly active mediator of airway responses in antigen-reactive airways of primates.