Effects of long-term estrogen replacement treatment on the blood pressure and expression of IR and IRS-1 in myocardium / 中南大学学报(医学版)

ABSTRACT

OBJECTIVE@#To determine the effects of long-term estrogen replacement treatment on blood pressure and expressions of insulin receptor (IR) and insulin receptor substrate-1 ( IRS-1) in myocardium.@*METHODS@#Fifty female SD rats were randomly divided into 3 groups. And then sham ( n = 16), ovariectomy (OVX, n = 17), and estrogen replacement treatment group (OVX + E2, n = 17) were established. Systolic blood pressure of tail artery was determined by tail-cuff technique before the operation and on week 12 after the operation. The expressions of IR and IRS-1 were measured by RT-PCR in myocardium of SD rats.@*RESULTS@#Blood pressure [ (118.75+/-2.77) mmHg] in OVX was significantly higher than that in the sham [ ( 103.86+/-1.84) mmHg, P 0.05 ). The difference of IR expression has no statistical significance among the 3 groups.@*CONCLUSION@#Long-term estrogen replacement treatment might protect cardiovascular system through decreasing the blood pressure and inducing the expression of IRS-1 in myocardium. However, plasma estrogen level doesn't significantly influence the IR expression.