Shen K Z, North R A
Vollum Institute, Oregon Health Sciences University, Portland 97201.
Neuroscience. 1992 Sep;50(2):345-53. doi: 10.1016/0306-4522(92)90428-5.
Whole-cell recordings were made from neurons of the rat locus coeruleus in a tissue slice removed from rat brain. Substance P caused an inward current in cells voltage-clamped at -60 mV. The effect of substance P was concentration-dependent (30 nM-3 microM) and was mimicked by similar concentrations of substance K and neuromedin K. The inward current resulted predominantly from an increase in membrane cation conductance; in potassium-free solutions it reversed polarity at about 12 mV. Substance P also reduced the conductance of an inwardly rectifying potassium current; this action was studied with low external sodium concentration. It is concluded that substance P excites rat locus coeruleus neurons by activating an intracellular transduction pathway leading to both cation conductance increase and potassium conductance decrease.
在从大鼠脑取出的组织切片中，对大鼠蓝斑核的神经元进行全细胞记录。P物质在电压钳制于 -60 mV 的细胞中引起内向电流。P物质的作用呈浓度依赖性（30 nM - 3 μM），并且类似浓度的K物质和神经降压肽K可模拟该作用。内向电流主要源于膜阳离子电导增加；在无钾溶液中，其反转电位约为12 mV。P物质还降低内向整流钾电流的电导；该作用在低细胞外钠浓度条件下进行研究。得出的结论是，P物质通过激活细胞内转导途径兴奋大鼠蓝斑核神经元，该途径导致阳离子电导增加和钾电导降低。
