FLUID TRANSPORT ACROSS RETINAL-PIGMENT EPITHELIUM IS INHIBITED BY CYCLIC-AMP
FLUID TRANSPORT ACROSS RETINAL-PIGMENT EPITHELIUM IS INHIBITED BY CYCLIC-AMP
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DOI：
10.1073/pnas.79.6.2111
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发表时间：
1982-01-01
期刊：
影响因子：
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通讯作者：
MACHEN, TE
中科院分区：
文献类型：
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作者：
MILLER, SS;HUGHES, BA;MACHEN, TE
测量了通过视网膜色素上皮(牛蛙)的液体转运。这些实验是使用电容探头技术和防水小室进行的，该小室允许以0.5-1.0nL/min的精度进行测量。在上皮细胞两侧使用相同的S液，在没有静水推动力的情况下，液体的净运动方向是从视网膜到脉络膜(吸收)。净传输速率.apprx。10nL/min(4.8µl/cm2/h)，与在其他两栖类上皮细胞中观察到的结果相当。线粒体解偶联剂2，4-二硝基苯酚将其还原为0，但相对不受哇巴因的影响，哇巴因抑制位于该上皮细胞顶膜上的Na+/K+泵。二丁酰cAMP和3-异丁基-1-甲基黄嘌呤(一种有效的磷酸二酯酶抑制剂)显著降低了液体的净吸收。这种cAMP依赖的液体转运可能是控制视网膜下腔液体量的重要机制。
Fluid transport across the retinal pigment epithelium (bullfrog) was measured. These experiments were carried out by using a capacitance probe technique and a water-impermeable chamber that allowed the measurements to be made with an accuracy of 0.5-1.0 nl/min. With identical Ringer''s solution on both sides of the epithelium, and in the absence of a hydrostatic driving force, the direction of net fluid movement is from the retina to the choroid (absorption). The net transport rate, .apprx. 10 nl/min (4.8 .mu.l/cm2 per h), is comparable to that observed in other amphibian epithelia. It is reduced to 0 by the mitochondrial uncoupler 2,4-dinitrophenol but is relatively unaffected by ouabain, which inhibits the Na+/K+-pump located on the apical membrane of this epithelium. A significant decrease in net fluid absorption was produced by dibutyryl cAMP and 3-isobutyl-1-methylxanthine (a potent phosphodiesterase inhibitor). This cAMP-dependent fluid transport may be an important mechanism for controlling the fluid volume in the subretinal space.