Wu J, Jin G Z
Department of Neurology, University of New Mexico School of Medicine, Albuquerque 87131, USA.
Brain Res. 1997 Nov 14;775(1-2):214-8. doi: 10.1016/s0006-8993(97)00960-8.
In the patch-clamp perforated whole-cell recording mode, tetrahydroberberine (THB), a novel dopamine (DA) receptor antagonist, inhibits not only DA-induced outward K+ currents, but also acetylcholine-, caffeine- or strychnine-induced outward current. However, THB does not affect either GABA- or glycine-induced Cl- currents, or non-NMDA receptor agonist-induced cation currents. As expected for a K+ channel blocker, THB evokes a downward current deflection accompanied by a decrease of conductance. It is concluded that the direct blockade of membrane K+ channels by THB underlies its inhibition of intracellular message-mediated outward currents.
在膜片钳穿孔全细胞记录模式下，新型多巴胺（DA）受体拮抗剂四氢小檗碱（THB）不仅抑制DA诱导的外向K+电流，还抑制乙酰胆碱、咖啡因或士的宁诱导的外向电流。然而，THB既不影响GABA或甘氨酸诱导的Cl-电流，也不影响非NMDA受体激动剂诱导的阳离子电流。正如K+通道阻滞剂所预期的那样，THB引起向下的电流偏转并伴有电导降低。得出的结论是，THB对膜K+通道的直接阻断是其抑制细胞内信息介导的外向电流的基础。
