INHALATION OF PLATELET-ACTIVATING-FACTOR INCREASES RESPIRATORY RESISTANCE IN RATS - DETERMINATION BY MEANS OF AN ASTOGRAPH UNDER NONANESTHETIZED CONDITIONS

Intratracheal administration of platelet-activating factor (PAF) to do gs, baboons, and humans has been shown to induce hyperreactivity of th e airways and contraction of the smooth muscle. However, it has not ye t been reported whether intratracheal administration of PAF to rats in duces hyperreactivity. In the present study, the authors estimated the respiratory resistance of rats during intratracheal administration of PAF in order to evaluate the reactivity of the airways to PAF. In bot h the nonsensitized group and the sensitized group of rats, intratrach eal administration of PAF induced an increase in respiratory resistanc e. The results obtained clarify that responsiveness to PAF exists in t he airways of rats.