Effects Of Estrogen On The Concentration Of Estrogen Receptor In Heart And Vascular Endothelial Cells And The Function Of Vascular Endothelial Cells Of Female Rats

Objective: After establishing the female rat models of ovariectomy, estrogen replacement therapy (ERT) and high cholesterol diet, we observed the effects of estrogen level change and hyperlipemia on the concentrations of estrogen receptor(ER) in heart and vascular endothelial cells(VECs). Considering the important role of VECs in coronary artery disease (CAD), we also observed the influence of estrogen on proliferation of VECs, and then investigated the influence of estradiol on expression of vascular cell adhesion molecule-I (VCAM-l) in surface of VECs. Methods: 1. 32 adult female rats were randomly divided into sham-operated group, ovariectomy group, ERT group and high cholesterol diet group. Radioimn抜unology method was used to measure the concentration of estradiol and progesterone (P), the receptor binding assay was employed to measure the level of estrogen receptor in heart and VECs. 2. Normal lung vascular cells of female rats were cultured with the blocks explanting method, and indirect immunofluorescent staining of antigen relative to factor VIII was used to identify VECs. The second generation cells were taken in experiment to measure the effect of different concentrations of 1 7-I3estradiol (E2) and testosterone(T) on proliferaton of VECs, and observe certain ratio of estradiol and testosterone on proliferaton of VECs, and also measure progesterone and certain ratio of estradiol and progesterone on proliferaton of VECs. MTT technique was applied to measure the proliferation of VECs. 3. The cells, which grew well after they were subcufurddtfor 5 wer? given different concentration of 1 7-f3E2 (with or witout espgen receptor antagonist tamoxifen) and cultured 48 hours. Then the cells were added interleuldn- 1 f3. Four hours later, the cells were collected to marked with anti-VCAM-1 monoclonal antibody of mouse and IgG tagged by FITC of goat anti-mouse. At last, the fluorescence level of the marked cells was measured with flowcytometery. Results: 1. Receptor binding assay showed the existence of estrogen receptor in heart and in VECs of female rats. 2. Bmax of ER in heart in ovariectomy group decreased significantly. And Bmax of ER in heart in high cholesterol group dropped apparently, but remained higher than that in ovariectomy group. Bmax of ER in heart in estrogen replacement therapy group was much higher than that in ovariectomy group (P<0.0 1). 3. The change of ER Bmax in lung VECs was same as in heart. 4. 1 7-f3E2 both at 3 x lO and at I 0 mol/L accelerated the proliferation of VECs in female rat lungs. Testosterone at 3x1091O~7 molIL had no apparent effect on the proliferation of VECs. But when the ratio of estradiol and testosterone was one, the proliferation of VECs was accelerated, but when the ratio was one percent, no proliferation was observed. 5. Progesterone at the concentrations of I 0~ and 1O mol/L had no effect on the proliferation of VECs. When the ratio of estradiol and progesterone was 3 and 3/100, the proliferation of VECs showed no significant difference among the groups, but if E2/P reached 3/10, the proliferation was significant. 6. Normal cultured VECs expressed VCAM-l in small amount, but the percent of cells marked with VCAM- 1 increased apparently after the they were stimulated by interleukin-lf3 (P<0.01)...