Battle T, Michel J B, Corman B
INSERM unité 367, Paris, France.
Biochem Biophys Res Commun. 1992 May 29;185(1):386-91. doi: 10.1016/s0006-291x(05)80997-0.
Atrial natriuretic factor increases the water permeability of the whole endothelium. This study investigates how it would affect the transcellular osmotic water permeability of bovine artery endothelial cells. The cyclic-GMP production by the isolated cells was maximal for 10(-6)M atrial natriuretic factor within 30 minutes at 37 degrees C. The cyclic-GMP protein kinase cell concentration was 1.87 +/- 0.15 ng/mg protein. The control apparent water permeability of the cells measured by light scattering was 195 +/- 11 microns/sec (n = 5). Membrane folding revealed by light and scanning electron microscopy indicated that their true water permeability values would be close to 20-40 microns/sec, similar to the values for lipid membranes. The energy activation calculated from the temperature dependence of water permeability between 15 degrees C and 37 degrees C was 9.3 kcal/mol. This value suggests water movement through the lipid bilayer and not through water channels. Atrial natriuretic factor 10(-6)M did not significantly increase the water permeability of the cells. Hence, atrial natriuretic factor-stimulated increase in water permeability of the endothelium is more related to changes in paracellular water pathways than in transcellular water flux.
心房利钠因子可增加整个内皮的水通透性。本研究探讨其如何影响牛动脉内皮细胞的跨细胞渗透水通透性。在37℃下，分离细胞产生的环磷酸鸟苷在30分钟内对10⁻⁶M心房利钠因子达到最大值。环磷酸鸟苷蛋白激酶细胞浓度为1.87±0.15 ng/mg蛋白。通过光散射测量的细胞对照表观水通透性为195±11微米/秒（n = 5）。光镜和扫描电镜显示的膜折叠表明其真实水通透性值接近20 - 40微米/秒，与脂质膜的值相似。根据15℃至37℃之间水通透性的温度依赖性计算出的能量活化值为9.3千卡/摩尔。该值表明水通过脂质双层而非水通道移动。10⁻⁶M心房利钠因子并未显著增加细胞的水通透性。因此，心房利钠因子刺激引起的内皮水通透性增加与细胞旁水途径的变化而非跨细胞水通量的变化更相关。
