Degradation of vasoactive intestinal peptide in bronchial alveolar lavage fluid

Vasoactive Intestinal Peptide (VIP) is found in normal mammalian airway tissue and has been suggested to be the endogenous mediator of tracheobronchial smooth muscle relaxation. Since VIP has been postulated as having a neurotransmitter role, a mechanism for rapid inactivation is a necessary criterion. To date there have been no reports on the potential influence of enzymatic metabolism on the functioning of VIP in human airway smooth muscle or about specitic enzymes that degrade VIP in the human lung. In order to most closely inimic the inetabolic conditions present when VIP would be administered by aerosol, we have chosen to examine the degradation of VIP in bronchial alveolar lavage (BAL) fluid