In two studies vasoactive intestinal peptide (VIP) was administered intravenously to two groups of eight in-patient volunteers recovering from severe acute asthma. VIP (6 pmol/kg/min) infusion caused significant (p<0.01) increase in peak expiratory flow rate (PEFR) of 26±9 (SEM) l/min after 30 minutes infusion compared with a bronchodilation of 39±19 l/min seen with salbutamol (5 mcg/min). Following pretreatment with nebulized ipratropium bromide, VIP infusion caused a significant (p<0.02) bronchodilation of 25 l/min. VIP is a broncholdilator in severe asthma, although its effects are less than conventional medication. Reflex mechanisms are unlikely to explain the bronchodilatory effect of intravenous VIP. © 1986.
Morice, A. H., & Sever, P. S. (1986). Vasoactive intestinal peptide as a bronchodilator in severe asthma. Peptides, 7(SUPPL. 1), 279–280. https://doi.org/10.1016/0196-9781(86)90202-0