ABSTRACT
Objective: To investigate the effect of electroacupuncture (EA) on rat with diet induced obesity (DIO) and to explore the possible neurochemical mechanisms using the technique of immumohistochemisty. Methods:To establish DIO rat model by feeding the animals with high fat diet for 14 weeks. DIO rats were randomly divided into 4 groups: (1) 2Hz EA group, (2) 100Hz EA group, (3) restrain control group,(4) diet resistance (DR) group,(5) DIO group and (6) normal control group. EA treatment: (1) The acupoints used were Zusanli and Sanyinjiao on both legs. (2) The intensities of stimulation were 0.5, 1.0 and 1.5mA for 10 mins each. EA treatment was administered 3 times per week. Food intake and body weight were measured daily for 4 weeks. (3) The changes of the expression of ? melanocyte stimulating hormone (? MSH) in the hypothalamic arcuate nucleus (ARC) were measured with immunohistochemical semiquantitative analysis. Results: (1) The food intake and body weight of 2 Hz EA group and 100 Hz EA group were decreased significantly compared with the restrain control group and DIO group. (2) The number of ? MSH positive cells in hypothalamic ARC in 2 Hz EA and 100 Hz EA group was significantly higher than that in restrain control group and DIO group. The number of ? MSH positive cells in hypothalamic ARC in DIO group is significantly lower than those in DR group or normal control group. Conclusion: A decrease of ? MSH level in hypothalamus may be associated with diet induced obesity. The therapeutic effect on obesity produced by EA may be accounted for by the stimulation of pro opio melanocortin neurons in hypothalamic ARC to release ? MSH, which inhibits food intake , resulting in a decrease of body weight.
ABSTRACT
AIM To investigate effect of urotensin Ⅱ (UⅡ)on proliferation of aort a smooth muscle cells （ASMC）of rat and study the signal transduction pathway o f it. METHODS In cultured ASMC of rat, UⅡ was used to stimulate proliferation of these cells and levels of ［3H］-TdR incorporation were used to evaluate the speed of DNA synthesis, and different inhibitors were used to s tudy the action of different signal transduction pathway of mitogenic effect of UⅡ on VSMC. RESULTS 1×10-9～1×10-7 mol*L- 1 UⅡ caused marked concentration-dependent increasing of ［3H］-TdR i ncor poration of ASMC. ［3H］-TdR incorporation of 1×10-9,1×10-8 and 1×10-7 mol*L-1 UⅡ were 22%（P<0.05）, 57%（P<0.01）and 65%（P<0.01）higher than control. Nicardipine, H7, W7 and PD98059 , which are inhibitors of calcium channel, PKC, CaM-PK and MAPK respectively, inhibited the effects of UⅡ obviously, with the inhibitory rate by 55%（P< 0.01）, 27%（P<0.01）,18%（P<0.05）and 16%（P<0.05）respectively . CONCLUSION UⅡ is a strong mitogen for VSMC and the mitogenic e ffect of UⅡ is probably mediated by Ca2+, PKC, CaM-PK and MAPK signal tr ansduction pathway.
ABSTRACT
AIM To investigate effect of urotensin Ⅱ (U Ⅱ )on proliferation of aorta smooth muscle cells (ASMC) of rat and study the signal transduction pathway of it. MEfHODS in cultured ASMC of rat, U Ⅱ was used to stimulate proliferation of these cells and levels of [3H]-TdR incorporation were used to evaluate the sped of DNA synthesis, and different inhibitors were ed to study the action of different signal transduction pathway of mitogenic effect of UⅡ on VSMC. RESULTS. 1 ? 10-9~l ? 10-7 mol. L-l U Ⅱ caused marked concentration-de pendent increasing of [3H]-TdR incorporation of ASMC [3H]-TdR incorporation of 1 ? 10-9, 1 ? 10-8 and １ ? 10-7 mol. L－l U Ⅱ were 22%'(P