Objective:To investigate the important relations between Helicobacter pylori (H.pylori) infection and serum gastrin level and nitric oxide synthase (NOS) activity in order to look for a method treating diseases associated with H.pylori.Methods:Before and after triple therapy against H.pylori with omeprazole 20mg twice a day

clarithromycin 0.25

and metronidazole 0.2 3 times a day for two weeks

fifty-nine with active DU and H.pylori positive

and 39 cases with non-ulcer dyspepsia as control were determined for NOS activity of gastric mucosa and fast serum gastrin level.Results:Patients with DU activity and H. pylori infection

before treatment

had an increased in NOS activity of gastric mucosa and fast serum gastrin level than those after treatment and the control

there were great importance( P <0.001 and P <0.005 respectively);NOS activity and gastrin level between the patients with healed DU and the control were of no significant difference.The changes of NOS activity were not significant whether H.pylori eradicated or not

it maybe link with no-healed peptic ulcer and a few patients

but there was a significant decrease of gastrin level when H.pylori was eradicated.Conclusion:Our findings showed H.pylori infection could increase NOS to promote gastrin secretion

and lead to gastroenterological diseases such as peptic ulcer.It clearly implied to us:through taking some measures to inhibit NOS activity to treat diseases associated with H.pylori.