Puro D G
Department of Ophthalmology, University of Michigan School of Medicine, Ann Arbor 48105.
Glia. 1991;4(5):456-60. doi: 10.1002/glia.440040505.
The cell-attached and excised patch configurations of the patch clamp technique were used to study stretch-activated ion channels in Muller glial cells that were obtained from postmortem adult human retinas and were maintained in culture. A stretch-activated channel permeable to monovalent and divalent cations was found. Ion channels of this type have not been demonstrated previously in glial cells, though indirect evidence has suggested that such stretch-activated channels may help mediate a compensatory response of glia to swelling. Consistent with a possible role for volume regulation is the finding that the activation of calcium-permeable stretch-sensitive channels is associated with an increase in the activity of calcium-activated potassium channels. Activation of potassium channels to produce an efflux of potassium with a subsequent loss of anions and cell water could be an effective mechanism to decrease glial cell volume.
采用膜片钳技术的细胞贴附式和膜片切除式配置，研究从成人死后视网膜获取并在培养中维持的穆勒胶质细胞中的牵张激活离子通道。发现了一种对单价和二价阳离子通透的牵张激活通道。尽管间接证据表明这种牵张激活通道可能有助于介导胶质细胞对肿胀的代偿反应，但此前尚未在胶质细胞中证实此类离子通道。与体积调节的可能作用一致的是，钙通透牵张敏感通道的激活与钙激活钾通道活性的增加相关。激活钾通道以产生钾外流，随后阴离子和细胞内水分流失，可能是降低胶质细胞体积的有效机制。
