雌激素及其拮抗剂对大鼠脂代谢和血管活性肽水平的影响

Effects of Estrogen and its Antagonist on Lipid Metabolism and the Levels of Vasoactive Peptides in Rat

以假手术大鼠（Sham）作为对照组，切除大鼠双侧卵巢（OVX）后，血浆17β-雌二醇（17β-E2）水平下降48％。体重增加17％（P＜0．001），血清总胆固醇（TC）含量升高约50％（P＜0．001），甘油三酯（TG）含量降低30％（P＜0．01）。OVX后进行雌激素替代疗法（ERT）各组（ERT1-3）的TC和TG的含量分别下降（P＞0．05）到和升高（P＜0．01）至高于对照组的水平。给于雌激素受体拮抗剂──它莫西芬（TAM）的各组（TAM，OVX＋TAM，ERT3＋TAM）中，血清TC和TG含量均低于对照组（P＜0．01～P＜0．001）。此外，OVX组血浆降钙素基因相关肽（CGRP）和内皮素水平也分别降低为对照组的69％和89％（P＜0．05）。提示卵巢激素主要是雌激素通过其受体介导参与大鼠脂代谢和体重的调节，ERT和TAM对OVX大鼠血清TC浓度及体重的调节产生有利影响。OVX大鼠血浆CGRP和内皮素水平的调节可能与雌激素水平变化有关。

Ovariectomized(OVX) rats revealed a 48% reduction of 17 beta estradiol (17β-E2) in the plasma level, a 17% increase in body weight (P<0.001), a 50% increase of serum total cholesterol (TC)(P<0.001) and a 30% decrease of serum triglyceride (TG)(P<0.001), as compared to sham operated control rats. Estrogen replacement therapy (ERT) in ERT1-3 groups, where OVX rats received estradiol, reduced serum TC to control level gradually (P>0.05) and increased serum TG concentrations over that of control significantly (P<0.01). When tamoxifen (TAM) was given alone or together with ovariectomy (OVX), the serum levels of TC and TG in TAM, OVX+TAM and ERT3+TAM groups were lower than those of control (P<0.01~0.001 ), respectively. In addition,the plasma levels of CGRP and endothelin in OVX rats were reduced to 69% and 89% (P<0.05) of control respectively. This study suggested that estrogen and its receptor may be involved in the regulation of lipid metabolism and body weight in rats. ERT and TAM was found to be benificial in the correction of serum cholesterol concentration and of body weight in OVX rats. Regulation in the plasma levels of CGRP and endothelin in OVX rats may be secondary to the changes of plasma estrogen levels.