[A clinical study on determination of plasma vasoactive intestinal peptide and the relationship between plasma...

Vasoactive intestinal peptide (VIP), which is localized in normal human lung, may play an important role in regulating bronchial tone, pulmonary blood flow and mucus secretion. The level of plasma VIP and bronchial responsiveness were studied in patients with asthma, chronic bronchitis and the healthy subjects. The results showed that the level of plasma VIP in asthmatic patients during acute attack and symptom-free period was significantly lower than that in the patients with bronchitis and the healthy subjects and it is negatively correlated with the bronchial hyperresponsiveness. It is suggested that both asthmatic attack and bronchial tone are related with the decrease of VIP.