Adjustment of acupuncture on arcuate nucleus of hypothalamus in obese rats

Zhicheng LIU; Fengmin SUN; Jinhong YUAN; Junzuo JIANG; Yunling YI; Yani LU

ABSTRACT

BACKGROUND:

The abnormality of the function of arcuate nucleus may be an important factor of obesity. It has been known that the mechanisms of acupuncture in treating obesity are related to nervous and neurohumoral regulation. What is the regulating effect of acupuncture on the function of arcuate nucleus?

OBJECTIVE:

To study the effects of acupuncture on the function of arcuate nucleus of obese rats, and further investigate central nervous functional mechanism of reducing weight by acupuncture.

DESIGN:

Randomized controlled study based on the experimental animals.

SETTING:

Acupuncture institute in second clinical medical college of a university of traditional Chinese medicine, and a population management college.MATERIALS This experiment was carried out in the Acupuncture Institute of Second Clinical Medical College, Nanjing University of Traditional Chinese Medicine between April and October 2002. One-month old male SD rats just in ablactation were selected.

METHODS:

Rats fed with ordinary wholesome rat-feed were in the normal group. The successfully established experimental obese rats models were randomly divided as control group and acupuncture group with 12 rats in each group. Rats in the acupuncture group were given acupuncture treatment for 14 days, and rats in the normal and control groups were put into rat fixation-machine for 15 minutes every day, lasting for 14 days. Body mass, Lee' s index, body lipid, level of central and peripheral leptin and insulin(INS) as well as the frequency of spontaneous discharge of nerve cell in the arcuate nucleus(ARC) of hypothalamus in obese rats were observed with nervous electrophysiological and nervous biochemical technology before and after acupuncture.MAIN OUTCOME

MEASURES:

① Effect of acupuncture on obesity index, fat contents of pericardium, kidney and epididymis of experimental obese rats. ② Effect of acupuncture on the frequency of spontaneous discharge of ARC nerve cell of hypothalamus in obese rats. ③ Effect of acupuncture on the contents of hypothalamic and serum leptin and INS of rats in each groups. ④ Correlation of the frequency of spontaneous discharge of ARC nerve cell of hypothalamus with the level of hypothalamic leptin and INS.

RESULTS:

The body mass[(517.74±29.35) g], Lee' s index (319.85 ± 3.96) and body fat content of obesity rats [ (13.88 ± 1.32) g] were all significantly higher than those in the normal rats, the differences were significant(P ＜ 0.01); the frequency of spontaneous discharge of nerve cell in ARC of hypothalamus in obese rats [ (3.12 ± 1.92) Hz] were all markedly lower than those of the normal rats[ (8.99 ± 2.71 ) Hz], the differences were significant (P ＜ 0.01 ); the frequency of spontaneous discharge of nerve cell in ARC was negatively correlated with body mass, Lee' s index and body lipid( r = -0. 592, -0. 672, -0. 521 ) . Acupuncture significantly increased the frequency of spontaneous discharge of nerve cell in ARC of hypothalamus in obese rats [(9.75 ±2.02) Hz] as compared with the control group, the differences were significant( P ＜ 0. 01 ).

CONCLUSION:

The good regulating effect of acupuncture on the function of arcuate nucleus of hypothalamus might be one of mechanisms in the antiobesity of acupuncture.