Objective:To explore into the underlying cellular and molecular mechanisms of acupuncture in anti-obesity. Methods:Thirty-six SD rats were evenly randomized into control

model and electroacupuncture (EA) groups. Obesity model was established by feeding the rats with high fat diet forage. "Zusanli"(ST 36) and "Neiting"(SI 34) were punctured and then stimulated electrically by an EA therapeutic apparatus (10 Hz

1.5 V

10 min)

once daily

continuously for 14 days. The expression of neuropeptide Y (NPY) gene in the hypothalamus tissue was determined with RT-PCR and Northern Blot techniques

and the contents of plasma and hypothalamic NPY were measured with radioimmunoassay. Changes of body weight

Lee's index and weight of fat tissue around the pericardium

kidney and epididymis were also observed before and after acupuncture. Results: Compared with control group

the body weight

Lee's index and body fat in model group increased markedly (P< 0.05～0.01)

and when compared with model group

these indexes of EA group lowered significantly (P<0.05)

showing that EA could reduce body weight. Comparison among three groups displayed that NPY contents in the serum and hypothalamic tissue of the model group were significantly higher than those of control group (P<0.01); and those of EA group were considerably lower than those of model group (P<0.01). RT-PCR and Northern Blot analysis displayed that compared with control group

NYP mRNA expression of model group increased significantly (P<0.01)

while after acupuncture treatment NYP mRNA expression was reduced significantly in comparison with that of model group (P<0.05～0.01). Conclusion: Acupuncture induced reduction of serum and hypothalamic NPY levels and suppression of NPY mRNA over-expression in the hypothalamus may be its important cellular and molecular mechanisms in resisting obesity.