Effects of long-term estrogen replacement treatment on the blood pressure and expression of IR and IRS-1 in myocardium.
- Author:
Mei-lian LIU
1
;
Xia XU
;
Ping XIE
;
Jin LU
;
Shu-hua CHEN
;
Wei-min ZENG
;
Hui-ping SONG
Author Information
1. Department of Biochemistry, Institute of Biological Science and Technology, Central South University, Changsha 410078, China.
- Publication Type:Journal Article
- MeSH:
Animals;
Blood Pressure;
drug effects;
Estradiol;
pharmacology;
Estrogen Replacement Therapy;
Female;
Insulin Receptor Substrate Proteins;
Myocardium;
metabolism;
Ovariectomy;
Phosphoproteins;
biosynthesis;
genetics;
Rats;
Rats, Sprague-Dawley;
Receptor, Insulin;
biosynthesis;
genetics;
Time Factors
- From:
Journal of Central South University(Medical Sciences)
2005;30(1):38-56
- CountryChina
- Language:Chinese
-
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 ] and OVX + E2 [( 107.83+/-3.24) mmHg, P < 0.05 ] rats. Expression of IRS-1 in OVX group was significantly lower ( 1.2588+/-0.1045)than that in the sham(2.2089+/-0.0988, P <0.05) and OVX + E2 groups ( 1.9100+/-0.1230, P <0.05 ). However, there was no difference on blood pressure and expression of IRS-1 between sham and OVX + E2 groups (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.
