Potter S M, Dennedy M C, Morrison J J
BJOG. 2002 Oct;109(10):1126-31. doi: 10.1111/j.1471-0528.2002.01540.x.
To investigate the direct effects of corticosteroids on human umbilical artery resistance, in vitro.
Prospective laboratory study.
University teaching hospital.
Umbilical artery samples were obtained following normal, term deliveries (n = 50) and dissected rings were suspended for isometric recording under physiological conditions. The effects of hydrocortisone (10(-9) - 10(-4) M), dexamethasone (10(-9) - 10(-4) M) and betamethasone (10(-9) - 10(-4) M) on umbilical artery resistance were measured in vitro.
Changes in umbilical artery resistance, in vitro.
Hydrocortisone (n = 12) exerted a vasodilatory effect on human umbilical artery at all concentrations studied compared with vehicle control experiments (n = 12) (P < 0.0001). The mean net relaxant effect of hydrocortisone ranged from 11.77% (10(-9) M) to 57.01% (10(-4)). Both exogenous compounds, dexamethasone (n = 12) and betamethasone (n = 12), similarly exerted a significant relaxant effect on human umbilical artery tone (P < 0.05-0.01), compared with vehicle control experiments (n = 12). The mean net relaxant effect of dexamethasone ranged from 14.43% (10(-9) M) to 38.12% (10(-4)) and that of betamethasone ranged from 6.02% (10(-9) M) to 42.30% (10(-4)), in a cumulatively increasing fashion. There was a non-significant trend towards a greater vasodilatory effect of dexamethasone than betamethasone at lower bath concentrations studied.
Corticosteroids exert a direct and potent vasodilatory effect on human umbilical artery resistance in vitro, thus providing an explanation for the previously unexplained vascular effects associated with antenatal administration of corticosteroids.
在体外研究皮质类固醇对人脐动脉阻力的直接影响。
前瞻性实验室研究。
大学教学医院。
在正常足月分娩后获取脐动脉样本（n = 50），将分离的血管环在生理条件下进行等长记录。在体外测量氢化可的松（10⁻⁹ - 10⁻⁴ M）、地塞米松（10⁻⁹ - 10⁻⁴ M）和倍他米松（10⁻⁹ - 10⁻⁴ M）对脐动脉阻力的影响。
体外脐动脉阻力的变化。
与溶媒对照实验（n = 12）相比，在所研究的所有浓度下，氢化可的松（n = 12）对人脐动脉均有舒张作用（P < 0.0001）。氢化可的松的平均净舒张效应范围为11.77%（10⁻⁹ M）至57.01%（10⁻⁴）。与溶媒对照实验（n = 12）相比，两种外源性化合物地塞米松（n = 12）和倍他米松（n = 12）同样对人脐动脉张力有显著的舒张作用（P < 0.05 - 0.01）。地塞米松的平均净舒张效应范围为14.43%（10⁻⁹ M）至38.12%（10⁻⁴），倍他米松的平均净舒张效应范围为6.02%（10⁻⁹ M）至42.30%（10⁻⁴），呈累积增加趋势。在所研究的较低浴槽浓度下，地塞米松的舒张作用比倍他米松有不显著的增强趋势。
皮质类固醇在体外对人脐动脉阻力有直接且强效的舒张作用，从而为产前使用皮质类固醇相关的先前无法解释的血管效应提供了解释。
