Objective To explore the mechanism of ginger-partitioned moxibustion in the treatment of cold-damp stagnation type primary dysmenorrhea(PD)patients.Methods A total of 209 PD outpatients of cold-damp stagnation type from 3 hospitals were randomized into moxibustion group(n=105)who were treated with ginger-partitioned moxibustion

and control group(n=104)who were asked to take Yueyue Shu Granules(an effective patent drug for PD).Ginger-partitioned moxibustion was applied to Shenque(CV 8)and Guanyuan(CV 4)from the menstrual onset on for the first course and 3 days before the onset for the second and third course

continuously for 3 days.Before and after the treatment

plasma endothelin-1(ET-1)and serum nitric oxide(NO)contents in those patients(n=40/group)and normal women(n=20)experiencing menstrual period were determined by radioimmunoassay and nitrate reductase method.Results After the treatment

of the 105 and 104 cases in moxibustion and control groups

58 and 32 cured

37 and 33 markedly effective

5 and 24 effective

5 and 15 failed

with the effective rates being 95.24% and 85.58% respectively.The therapeutic effect of moxibustion group was significantly better than that of control group(P<0.05).Before treatment

in comparison with normal group

plasma ET-1 contents in both moxibustion and control groups were significantly higher(P<0.01)

while serum NO contents in these two groups markedly lower(P<0.01).After the treatment

self-comparison of both moxibustion and control groups showed that plasma ET-1 decreased significantly and serum NO levels in increased considerably(P<0.05

P<0.01)

and the therapeutic effect of moxibustion group was markedly superior than that of control group in lowering plasma ET-1(P<0.01).Conclusion Ginger-partitioned moxibustion is effective in relieving primary dysmenorrhea patients' abdominal pain

which may be closely associated with its actions in lowering plasma ET-1 level and raising serum NO contents.