Single‐channel characteristics of the large‐conductance anion channel in rat cortical astrocytes in primary culture

GLIA - Tập 9 Số 3 - Trang 227-237 - 1993
Tuula O. Jalonen1
1Department of Biomedical Sciences, University of Tampere, SF-33101 Tampere, Finland

Tóm tắt

AbstractCultured rat cortical astrocytes, in addition to a variety of voltage‐sensitive potassium channels, also express anion channels. However, the behavior and regulation of these anion channels have been far less studied. This paper describes a patch‐clamp study on a voltage‐sensitive 200–300 pS high‐conductance single‐channel anion current, which seems to possess at least five different open sublevels or, alternatively, be formed froin five or more small‐conductance ion channels linked together. This channel is voltage dependent, showing a bell‐shaped open probability curve with highest open probability close to the reversal potential (zero‐current). Although potassium channels are commonly detected in astrocytes in cell‐attached and excised patches with both normal osmolarity and hypoosmotic solutions, the occurrence of the anion channel is clearly increased in isolated patches when hypoosmotic bath solutions are used. Also, cell aging in culture and the preparation of secondary cell cultures by trypsinization seem to increase the rate of occurrence of the anion channel. Though this channel is more routinely seen when a membrane patch is excised from the cell, occasionally cell‐attached configurations with instant channel activity can be formed. While the modulation of this anion channel was being studied, it was found to be blocked by an anion transport inhibitor, L‐644,711, reported to affect cell volume regulation in astrocytes. © 1993 Wiley‐Liss, Inc.

Từ khóa


Tài liệu tham khảo

10.1016/0304-3940(88)90148-6

10.1007/BF00232319

10.1002/glia.440010104

10.1016/0896-6273(90)90091-S

10.1098/rspb.1985.0063

10.1016/S0006-3495(83)84344-6

10.1073/pnas.85.23.9336

10.1113/jphysiol.1989.sp017521

10.1126/science.1379742

10.1021/jm00155a038

10.1007/BF01871605

10.1085/jgp.27.1.37

10.1098/rspb.1986.0055

10.1098/rspb.1984.0041

10.1016/S0006-3495(90)82622-9

10.1007/BF00656997

10.1113/jphysiol.1988.sp017229

Hille B., 1984, Ionic Channels of Excitable Membranes

10.1113/jphysiol.1949.sp004310

Hoffmann E. K., 1991, Advances in Comparative & Environmental Physiology, Vol. 9. Volume and Osmolality Control in Animal Cells, 140

10.1016/0736-5748(84)90030-3

10.1098/rspb.1988.0061

10.1111/j.1748-1716.1989.tb08709.x

Jalonen T., 1991, Potassium and anion channels opened by osmotic gradients across astrocyte plasma membranes, Soc. Neurosci. Abstr., 17, 57

10.1111/j.1749-6632.1991.tb15669.x

10.1007/978-3-642-76226-0_4

Kimelberg H. K., 1992, Astrocytic edema in CNS trauma, J. Neurotrauma, 9, S71

10.1002/glia.440010307

10.1016/0006-8993(90)90836-Z

Kimelberg H. K., 1990, Current and Future Trends in Anticonvulsant, Anxiety, and Stroke Therapy, 363

10.1161/01.STR.23.1.93

10.1016/0168-0102(90)90047-I

10.1007/BF00370515

10.1038/319058a0

10.1007/BF01187234

10.1038/265751a0

10.1111/j.1460-9568.1991.tb01677.x

10.1016/0304-3940(89)90515-6

10.1016/0898-6568(89)90018-1

McGill J. M., 1992, Characterization of high‐conductance anion channels in rat bile duct epithelial cells, Am. J. Physiol., 262, G703

10.1002/glia.440040513

10.1038/260799a0

10.1002/bbpc.198800256

10.1523/JNEUROSCI.07-01-00101.1987

O'Connor E. R., 1991, Effect of calcium on astrocyte volume regulation, ion and amino‐acid release, Soc. Neurosci. Abstr., 17, 56

10.1523/JNEUROSCI.13-06-02638.1993

10.1002/glia.440050104

10.1016/0166-2236(92)90052-A

10.1139/y87-165

10.1161/01.RES.70.4.679

10.1152/ajpcell.1992.262.4.C1056

10.1007/BF00231909

10.1172/JCI114391

10.1007/BF00581325

10.1007/BF00581324

10.1152/ajpcell.1989.256.6.C1111

Thông tin
Thông tin xuất bản

GLIA

Tập 9 Số 3

227-237

Thông tin tác giả