[Functional evaluation of possible cytokine receptors on airway smooth muscle: modification of airway smooth muscle responses by cytokines].

Recently, the role of activated T-cell derived cytokines in the pathophysiology of asthma has been recognized. In this study, we evaluated the effects of interleukin-2 (IL-2) and gamma interferon (IFN-gamma) on contractile and relaxing responses of guinea-pig tracheal strips in isometric tension measurement system. IL-2 enhanced carbachol (Carb)- and KCl-induced contraction, and attenuated isoproterenol (Iso)-induced relaxation. IFN-gamma had little effect on Carb and KCl contraction, but enhanced Iso relaxation. These effects of cytokines were abolished by denuding epithelium from tracheal strips. These results suggest that IL-2 and IFN-gamma are able to affect functions of non-immune cells in the airway, and that the airway epithelium has some role in the effects of cytokines on airway responses.