VIP and acute respiratory distress syndrome: Next, we confirmed that the combination of pseudoephedrine and emodin could activate the expression of the VIP/cAMP/PKA signal axis in the lung tissue of the ALI rats, significantly inhibiting IκBα phosphorylation and the dissociation of p65 and the phosphorylation of p65 in the nucleus, thereby blocking the transcription and expression of inflammatory mediators and immune-related genes.