Figure 1.

Effect of 100 μM L-NAME, 100 μg ml⁻¹ poly-L-arginine, 100 μg ml⁻¹ poly-L-arginine+100 μM L-NAME, 25 u ml⁻¹ heparin, 100 μg ml⁻¹ poly-L-arginine+25 u ml⁻¹ heparin, and 100 μg ml⁻¹ poly-L-arginine+25 u ml⁻¹ heparin+100 μM L-NAME on methacholine-induced constriction of intact perfused guinea-pig tracheae. Methacholine-induced constriction of the perfused airway preparations was measured as an increase in differential pressure (ΔP) at constant flow and normalized to the response of 40 mM KCl (EL). Results are means±s.e.mean of 3–8 experiments.