The effects of estrogen and progesterone on vascular reactivity of endothelium-denuded human uterine artery

Hong, Suk Woo; Park, Byung Moo; Hur, Min; Lee, Moo Yeol

Abstract

OBJECTIVES
The present study was performed to investigate whether estrogen and progesterone induce the change of vascular tone in endothelium-denuded human uterine artery and vascular reactivity may be mediated by intracelluar calcium modulation through receptor- and voltage-dependent calcium channels. METHODS: The uterine arteries were obtained at the time of hysterectomy from 28 women followed by denudation of endothelium. After confirmation of functional integrity of endothelium-denuded uterine artery, vascular reactivity was measured by using isometric force transducer and recorded by physiograph. Contraction was induced by 10-6 M norepinephrine and 35mM high concentrated potassium chloride solution which activated receptor-dependent calcium channel and voltage-dependent calcium channel, respectively.Thereafter estradiol of 4 different concentrations from 3x10-11M to 3x10-8M was administered. Progesterone was also administered to endothelium-denuded uterine artery which was contracted by 10-6M norepinephrine and high potassium chloride solution. To evaluate the effect of additional progesterone on vascular smooth muscle relaxation effect of estrogen,4 different progesterones in concentrations from 3x10-8M to 3x10-5M were given to vascular smooth muscle which was initially pretreated with norepinephrine followed by relaxation of estradiol. RESULTS: Estradiols from 3x10-11M to 3x10-8M showed in significant dose-dependent vascular relaxation. Progesterones result in significant decrease in vascular contraction in concentration dependent manner. Additional progesterone on estrogenic effects also results in significant decrease in vascular contraction. CONCLUSION: Estradiol may have endothelium independent vasorelaxation effect in human uterine artery. These vasorelaxant effects may be mediated through antagonistic action for receptor-and voltage-dependent calcium channels in vascular smooth muscle. Progesterone also bring about vasorelaxation by same action in endothelium-denuded vascular smooth muscle. On estrogen induced vascular relaxation, progesterone results in additional vasorelaxation.