Estrogen modulates ileal basolateral membrane lipid dynamics and Na+-K+-ATPase activity.
Estrogen modulates ileal basolateral membrane lipid dynamics and Na+-K+-ATPase activity.
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雌激素调节回肠基底外侧膜脂质动力学和 Na -K -ATP 酶活性。
DOI：
10.1152/ajpgi.1988.254.5.g687
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Medow,MS
中科院分区：
文献类型：
--
作者：
Schwarz,SM;Bostwick,HE;Medow,MS
研究了乙炔雌二醇对兔小肠基底外膜脂质结构和Na+-K+- atp酶活性的影响。乙炔雌二醇是一种合成雌激素，具有抑制胆固醇的特性，并倾向于改变肝细胞和回肠刷状膜流动性。利用荧光团1,6-二苯基-1,3,5-己三烯和DL-12-（9-蒽基）硬脂酸，在基底侧膜和从回肠分离的膜脂脂质体中发现荧光各向异性和流动性的倒数增加。流动性的改变伴随着双层磷脂的显著降低（0.37 vs 0.48 mumol/mg蛋白，P < 0.01），胆固醇与磷脂的摩尔比（0.85 vs 0.61, P < 0.02）和膜饱和脂肪酸含量的增加。雌激素介导的物理化学变化与回肠基底外侧膜Na+-K+- atp酶特异性活性的显著降低有关（100.0比185.8 nmol Pi.min-1）。毫克蛋白1;P < 0.02)。体外膜流化后，荧光各向异性和Na+-K+- atp酶特异性活性均恢复控制值。因此，这些数据表明，乙炔雌二醇对基底外侧膜脂动力学的影响仅限于回肠，并与Na+-K+- atp酶活性的抑制有关。这些结构和功能的改变似乎部分与雌激素治疗后磷脂可得性的特异性改变有关。
The effects of ethinyl estradiol, a synthetic estrogen with cholestatic properties and a propensity to alter hepatocyte and ileal brush-border membrane fluidity, on lipid structure and Na+-K+-ATPase activity of rabbit small intestinal basolateral membranes were determined. Utilizing the fluorophores 1,6-diphenyl-1,3,5-hexatriene and DL-12-(9-anthroyl)stearic acid, increases in fluorescence anisotropy, the reciprocal of fluidity, were found in basolateral membranes and in membrane lipid liposomes isolated from ileum. Fluidity alterations were accompanied by a marked decrease in bilayer phospholipids (0.37 vs. 0.48 mumol/mg protein; P less than 0.01) and an increase in both the cholesterol-to-phospholipid molar ratio (0.85 vs 0.61; P less than 0.02) and membrane saturated fatty acid content. Estrogen-mediated physicochemical changes were associated with a significant reduction in ileal basolateral membrane Na+-K+-ATPase specific activity (100.0 vs. 185.8 nmol Pi.min-1.mg protein-1; P less than 0.02). Control values both for fluorescence anisotropy and for Na+-K+-ATPase specific activity were restored after in vitro membrane fluidization with benzyl alcohol. The data therefore indicate that ethinyl estradiol effects on basolateral membrane lipid dynamics are confined to the ileum and are associated with inhibition of Na+-K+-ATPase activity. These structural and functional changes appear to be related, in part, to specific modifications in the availability of phospholipid after estrogen treatment.