Objective To study the underlying mechanism of acupuncture of "Zusanli"(ST 36) in clinical treatment of spleen deficiency syndrome(SDS).Methods Twenty-six adult male Wistar rats were randomized into normal control group(n=6)

model group(n=8)

saline+model(saline) group(n=6) and acupuncture+model(acupuncture) group(n=6).The spleen deficiency syndrome model was duplicated by intragastric perfusion of 50% alcohol(1 mL/100 g

once) and vinegar(pH 3

1 mL/100 g

once daily for 10 d).Bilateral "Zusanli"(ST 36) was punctured with filiform needles which were manipulated for 1 min after insertion and retained for 20 min.The treatment was conducted once daily for 10 days.The contents of serum testosterone(T) and estradiol(E2)were detected by radioimmunoassay.The rats' physical strength was detected by exhausted swimming test in cool water.Results In comparison with the normal group

the duration of exhausted swimming

serum T and E2 contents and T/E2 were decreased significantly in the model group(P<0.05).Compared with the model group

the duration of exhausted swimming

serum T and E2 contents and T/E2 in the acupuncture group were upregulated significantly(P<0.05).No significant differences were found between the saline and control groups(P>0.05).Conclusion Acupuncture of "Zusanli"(ST 36) is able to reverse SDS-induced decrease of sexual hormones in spleen deficiency syndrome rats

which may contribute to its effect in improving physical strength.