Ostrowski N L, Young W S, Lolait S J
Laboratory of Cell Biology, National Institute of Mental Health, NIH, Bethesda, MD 20892-4068.
Endocrinology. 1995 Apr;136(4):1801-4. doi: 10.1210/endo.136.4.7895693.
Estrogens have been implicated in the sodium and fluid imbalances associated with the menstrual cycle and late pregnancy. An estrogen-dependent role for renal oxytocin receptors in fluid homeostasis is suggested by the present findings which demonstrate that estradiol benzoate treatment increases the expression of the oxytocin receptor messenger ribonucleic acid and 125I-OTA binding to oxytocin receptors in the renal cortex and medullary collecting ducts of ovariectomized female rats. Moreover, estradiol induced high levels of oxytocin receptor expression in outer stripe proximal tubules of ovariectomized female and adrenalectomized male rats. Proximal tubule induction was inhibited in a dose-dependent manner by the antiestrogen tamoxifen, but cortical expression of oxytocin receptors in macula densa cells was unaffected by tamoxifen. These data demonstrate cell-specific regulation of oxytocin receptor expression in macula densa and proximal tubule cells, and suggest a important role for these receptors in mediating estrogen-induced alterations in renal fluid dynamics by possibly affecting glomerular filtration and water and solute reabsorption during high estrogen states.
雌激素与月经周期及妊娠晚期相关的钠和液体平衡失调有关。本研究结果提示，肾催产素受体在液体稳态中具有雌激素依赖性作用，该结果表明，苯甲酸雌二醇处理可增加去卵巢雌性大鼠肾皮质和髓质集合管中催产素受体信使核糖核酸的表达以及125I-OTA与催产素受体的结合。此外，雌二醇在去卵巢雌性大鼠和肾上腺切除雄性大鼠的外髓质近端小管中诱导了高水平的催产素受体表达。抗雌激素他莫昔芬以剂量依赖的方式抑制近端小管的诱导，但致密斑细胞中催产素受体的皮质表达不受他莫昔芬影响。这些数据证明了致密斑和近端小管细胞中催产素受体表达的细胞特异性调节，并提示这些受体在介导雌激素诱导的肾液体动力学改变中可能发挥重要作用，可能是通过在高雌激素状态下影响肾小球滤过以及水和溶质的重吸收来实现的。
