Effects of Sex Hormones and Their Balance on the Proliferation of Rat Vascular Endothelial Cells

Abstract

Objective: To investigate the adjustment of estrogen, progesterone and testosterone on the proliferation of female and male rat vascular endothelial cells (VECs) separately. Methods: Rat lung VECs were cultured according to the block explanting method. MTT assay was used to measure the proliferation of VECs. Results: 17β-Estradiol (E₂) at 3 × 10^–8 and 3 × 10^–7 M accelerated the proliferation of female rat VECs (p < 0.01). E₂ at 3 × 10^–9, 3 × 10^–8 and 3 × 10^–7 M accelerated the proliferation of male rat VECs (p < 0.05). Tamoxifen, the estrogen receptor antagonist, could block the effect of estrogen on the proliferation of VECs. Testosterone at 3 × 10^–8 and 3 × 10^–7 M significantly increased the proliferation of male rat VECs (p < 0.05), but had no effect on female rat VECs. Progesterone at 10^–9 and 10^–8 M had no effect on female rat VECs alone. When the ratio of E₂ to progesterone was 3/10, the proliferation of female rat VECs was accelerated (p < 0.05). When the ratio of E₂ to testosterone was 1/1, the proliferation of female rat VECs was also hastened (p < 0.05). However, when the ratio was reduced to 1/100, the hastening effect disappeared. Conclusion: Estrogen can speed up the proliferation of female and male rat VECs, while progesterone has no effect on female rat VECs alone. The balance of the ratio of E₂ to testosterone, E₂ to progesterone may play an important role in the proliferation of female rat VECs.