Expression of estrogen receptor genes are associated with cardiac hypertrophy and expression of BNP in ovariectomized rats fed a high-fat diet (the OF group). Gene expression in rat ventricle showing the mRNA detection of BNP, NPR-A, Erα, and ERβ. The mRNA determination was made by polymerase chain reaction (PCR) using the whole hearts (n=4 for each group) from sham-operated rats fed control diet (SC); ovariectomized rats fed control diet (OC); sham-operated rats fed a high-fat diet (SF); and ovariectomized rats fed a high-fat diet (OF). mRNA values have been normalized with mRNA β-actin values. A–D are the ratio of BNP, NPR-A, ERα and ERβ expressed in arbitrary units respectively. (E) Representative ethidium bromide visualization of polymerase chain reaction (PCR) products. N=4 each group. The results were analyzed by two-way ANOVA followed by Bonferroni’s test. * p <0.05 vs. SC group; # p<0.05 vs. SC, OC and SF; Ω p<0.05 vs. SC and SF; (n=4, for each group).