Haws C M, Lansman J B
Department of Pharmacology, School of Medicine, University of California, San Francisco 94143-0450.
Proc Biol Sci. 1991 Jun 22;244(1311):185-9. doi: 10.1098/rspb.1991.0068.
Recordings of single-channel activity were made from cell-attached patches on cerebellar granule cells from normal and mdx mice. Recordings from mdx granule cells show the activity of ion channels that are open for seconds at negative holding potentials near rest. These channels are permeable to divalent cations and have a conductance of 8-10 pS with either Ca2+ or Ba2+ as the charge carrier in the patch electrode. Under similar recording conditions, channel activity is virtually absent from normal mouse granule cells. The absence of dystrophin in neurons, as well as in skeletal muscle, is associated with an increase in the activity of Ca(2+)- permeable ion channels. Increased channel activity may be an early event leading to pathophysiological accumulation of intracellular Ca2+ in Duchenne muscular dystrophy.
从正常小鼠和mdx小鼠的小脑颗粒细胞的细胞贴附式膜片上记录单通道活性。mdx颗粒细胞的记录显示，在接近静息的负性钳制电位下，离子通道的活性可持续数秒。这些通道对二价阳离子具有通透性，当膜片钳电极中以Ca2+或Ba2+作为电荷载体时，其电导为8 - 10 pS。在相似的记录条件下，正常小鼠颗粒细胞几乎没有通道活性。神经元以及骨骼肌中缺乏肌营养不良蛋白与Ca(2+)通透性离子通道活性增加有关。通道活性增加可能是导致杜兴氏肌营养不良症细胞内Ca2+病理生理积聚的早期事件。
