Gambling Lorraine, Dunford Susan, Wilson Catherine A, McArdle Harry J, Baines Deborah L
Development, Growth and Function Division, Rowett Institute, Aberdeen, Scotland, United Kingdom.
Kidney Int. 2004 May;65(5):1774-81. doi: 10.1111/j.1523-1755.2004.00593.x.
Estrogen and progesterone regulate alpha, beta, and gamma amiloride-sensitive epithelial sodium channel (ENaC) subunit mRNA levels in female rat kidney. Renal Na(+) handling differs between males and females. Further, within females Na(+) metabolism changes during the menstrual cycle and pregnancy. Electrolyte homeostasis and extracellular fluid volume are maintained primarily by regulated transport of Na(+) via the amiloride-sensitive Na(+) channel. This study examines the role of the female gender steroids in the regulation of expression of ENaC.
We measured ENaC subunit mRNA levels in rat kidney using Northern blotting. Kidneys were taken from male and females at different ages and from adult ovariectomized rats treated with 17-beta-estradiol benzoate (estrogen) and/or progesterone for 8 or 24 hours.
The abundance of alpha, beta, and gammaENaC mRNA was significantly higher in female compared to male rat kidneys from 10 weeks of age (P= 0.001, P= 0.004, and P= 0.02, N= 10, respectively). These differences were abolished in ovariectomized rats. Treatment of ovariectomized rats with estrogen increased alphaENaC mRNA abundance in the kidney at both 8 and 24 hours (P < 0.05, N= 6; and P < 0.05, N= 7, respectively). Progesterone inhibited the effect of estrogen on alphaENaC mRNA at 8 hours but when given alone increased gammaENaC mRNA (P < 0.05, N= 3). Neither hormone, alone or in combination, had any significant effect on betaENaC mRNA levels at 8 or 24 hours.
Female gonadal steroids differentially modulate expression of ENaC subunit mRNA in the rat kidney.
雌激素和孕酮可调节雌性大鼠肾脏中α、β和γ氨氯地平敏感上皮钠通道（ENaC）亚基的mRNA水平。雄性和雌性的肾脏钠（Na⁺）处理方式不同。此外，在雌性体内，月经周期和孕期的Na⁺代谢会发生变化。电解质稳态和细胞外液量主要通过氨氯地平敏感钠通道对Na⁺的调节转运来维持。本研究探讨了雌性性别类固醇在ENaC表达调节中的作用。
我们使用Northern印迹法测量大鼠肾脏中ENaC亚基的mRNA水平。肾脏取自不同年龄的雄性和雌性大鼠，以及接受苯甲酸雌二醇（雌激素）和/或孕酮处理8或24小时的成年去卵巢大鼠。
从10周龄起，雌性大鼠肾脏中α、β和γENaC mRNA的丰度显著高于雄性大鼠肾脏（分别为P = 0.001、P = 0.004和P = 0.02，N = 10）。去卵巢大鼠中这些差异消失。用雌激素处理去卵巢大鼠8小时和24小时后，肾脏中αENaC mRNA丰度均增加（分别为P < 0.05，N = 6；P < 0.05，N = 7）。孕酮在8小时时抑制雌激素对αENaC mRNA的作用，但单独使用时可增加γENaC mRNA（P < 0.05，N = 3）。单独或联合使用这两种激素，在8或24小时时对βENaC mRNA水平均无显著影响。
雌性性腺类固醇对大鼠肾脏中ENaC亚基mRNA的表达有不同的调节作用。
