[The influence of soybean isoflavone on expression of low density lipoprotein receptor (LDLR) mRNA in ovariectomied rats].

Objective: To investigate the effect of soybean isoflavone on blood lipid and the expression of LDLR mRNA in ovariectomied rats.
Methods: Forty eight Sprague-Dawley rats were divided randomly into four groups: Sham group (sham), OVX group (OVX), OVX + gemifibrozil (G) group (OVX + G) and OVX + isoflavone (ISO) group (OVX_ISO). in which the rats were treated with G or ISO for three months starting from two weeks after both sides of rat' s ovarietomy. Blood sample were taken out for determination of blood lipid. The liver tissue were taken out quickly, Isothiocyanate guanidine-phenol-chloroform was used to extract the total RNA from the liver and RT-PCR was used to detect the expression of LDLR mRNA.
Results: Compared with the OVX group, contents of TG, LDL-C and OX-LDL in serum in OVX + ISO group decreased remarkably, and the contents of HDL-C increased. LDLR mRNA in OVX + ISO group increased distinctively compared with OVX group and OVX + G group.
Conclusion: The level of mRNA of LDLR in liver decreas after ovariotormy and the soybean isoflavone may increase it by regulating the expression level of LDLR through transcription.