Vasopressin-mediated regulation of epithelial sodium channel abundance in rat kidney
Vasopressin-mediated regulation of epithelial sodium channel abundance in rat kidney
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DOI：
10.1152/ajprenal.2000.279.1.f46
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发表时间：
2000-07-01
影响因子：
4.2
通讯作者：
Knepper, MA
中科院分区：
文献类型：
--
作者：
Ecelbarger, CA;Kim, GH;Knepper, MA
在大鼠和兔的皮质集合管中，加压素增加了钠的转运。在这里，我们通过定量免疫印迹法研究了加压素对大鼠肾脏上皮钠通道(ENaC)亚单位(α、β和γ)丰度的影响。Brattleboro大鼠注射1-去氨基-[8-D-精氨酸]-加压素(DDAVP)7天后，全肾γ-ENaC带的丰度显著增加(分别为VeR的238%和288%)，而α-ENaC则温和而显著地增加(至Vev的142%)。类似地，Spraogue-Dawley大鼠禁水7天后，β-和伽马的含量显著增加，但α-ENaC的含量没有显著变化。给Brattleboro大鼠急性注射DDAVP(2nmoL)后，1h内所有ENaC亚基的丰度均有轻微但显著的增加。这些变化太慢，不能在加压素刺激集合管中钠重吸收的短期作用中发挥主要作用。ENaC丰度的长期增加应增加短期调节机制(未在本研究中定义)，以加强肾脏集合管中的钠转运。
Sodium transport is increased by vasopressin in the cortical collecting ducts of rats and rabbits. Here we investigate, by quantitative immunoblotting, the effects of vasopressin on abundances of the epithelial sodium channel (ENaC) subunits (alpha, beta, and gamma) in rat kidney. Seven-day infusion of 1-deamino-[8-D-arginine]-vasopressin (dDAVP) to Brattleboro rats markedly increased whole kidney abundances of band gamma-ENaC (to 238% and 288% of vehicle, respectively), whereas alpha-ENaC was more modestly, yet significantly, increased (to 142% of vehicle). Similarly, 7-day water restriction in Sprague-Dawley rats resulted in significantly increased abundances of beta- and gamma- but no significant change in alpha-ENaC. Acute administration of dDAVP (2 nmol) to Brattleboro rats resulted in modest, but significant, increases in abundance for all ENaC subunits, within 1 h. In conclusion, all three subunits of ENaC are upregulated by vasopressin with temporal and regional differences. These changes are too slow to play a major role in the short-term action of vasopressin to stimulate sodium reabsorption in the collecting duct. Long-term increases in ENaC abundance should add to the short-term regulatory mechanisms (undefined in this study) to enhance sodium transport in the renal collecting duct.