Jiang C, Haddad G G
Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06510.
Brain Res. 1993 Jun 18;614(1-2):352-6. doi: 10.1016/0006-8993(93)91055-w.
The effect of hypoxia on ionic currents was studied in acutely dissociated substantia nigra neurons. Using an external solution containing 0 mM Na+ and 0.5 mM Co2+, we found that overall whole-cell outward currents increased by 15-20% during 3-4 min of hypoxia. This current was voltage sensitive and could be completely blocked by TEA- and Cs+, suggesting that this is a K+ current. In cell-attached patches with 150 mM K+ in the external solution, we recorded a large-conductance outward current which was not observed during baseline and was reversibly activated by hypoxia. These results therefore provide the first direct evidence for the activation of K+ channels during O2 deprivation in central neurons.
在急性分离的黑质神经元中研究了缺氧对离子电流的影响。使用含有0 mM Na+和0.5 mM Co2+的外部溶液，我们发现在缺氧3 - 4分钟期间，整体全细胞外向电流增加了15 - 20%。该电流对电压敏感，并且可以被TEA和Cs+完全阻断，表明这是一种K+电流。在外部溶液中含有150 mM K+的细胞贴附式膜片中，我们记录到一种大电导外向电流，该电流在基线时未观察到，并且被缺氧可逆性激活。因此，这些结果为中枢神经元缺氧时K+通道的激活提供了首个直接证据。
