[Effects of estrogen level on the function of vascular endothelial cells and expression of vascular cells adhesion molecule].
OBJECTIVE: To observe the effect of estrogen level on the secreting function of vascular endothelial cells of female rats, and to study the regulation of content of estrogen receptor in VECs and the expression of vascular cells adhesion molecule-1 by estrogen level. METHODS: Radioimmunity was adopted to measure the content of endothelin and PGI2 in serum of female rats, and copper-niger reduction was chosen to measure the content of nitric oxide in serum. Radioligand binding and flow cytometry were used to measure the expression of estrogen receptor and vascular cells adhesion molecule-1 in female rat lung VECs respectively. RESULTS: (1) The content of nitric oxide (18 mumol/L +/- 8 mumol/L) and PGI2(8.5 pg/ml +/- 2.5 pg/ml) in blood decreased after castration and increased remarkably(31 mumol/L +/- 7 mumol/L, P < 0.05; 10.9 pg/ml +/- 3.4 pg/ml) after estrogen was supplemented. However, the content of endothelin changed conversely(170 pg/ml +/- 39 pg/ml, 100 pg/ml +/- 32 pg/ml, P < 0.05). (2) The content of ER in female rat lung VECs (6.7 +/- 0.5 fmol/10(6) cell) decreased remarkably after castration and increased after estrogen was supplemented(17.6 +/- 1.2 fmol/10(6) cell, P < 0.01). (3) The expression rate of VCAM-1 in VECs increased significantly after interleukin-1 beta acted on the cells(17.5% +/- 1.5%). 17-beta estradiol at the contents of 3 x 10(-8)-10(-6) mol/L all counteracted the increase in expression rate of VCAM-1 induced by interleukin-1 beta (15.4% +/- 1.42%, 12.4% +/- 0.34%, 8.7% +/- 0.27%, P < 0.01). CONCLUSION: The estrogen level influences the secreting of NO, PGI2 and ET of VECs, and influences the content of ER in VECs. 17-beta estradiol at 3 x 10(-8)-10(-6) mol/L counteracts the increase of VCAM-1 in VECs induced by interleukin-1 beta.