Differential changes in Substance P, VIP as well as neprilysin levels in patients with gastritis or ulcer

► Neuronal SP decreased in gastritis and it further decreased in the presence of H. pylori. ► VIP and NEP in both disease-involved and uninvolved mucosa decreased in gastritis or ulcer. ► Decreased levels of VIP and SP fragments might be responsible from chronic gastritis. ► VIP analogs might be used in chronic gastritis and ulcer. ► Decreased SP levels in H. pylori (+) patients may predispose to malignancy.