肾上腺素对牛蛙交感神经节细胞动作电位的影响。

Effects of adrenaline on the action potential of sympathetic ganglion cells in bullfrogs.

作者信息

Minota S, Koketsu K

出版信息

Jpn J Physiol. 1977;27(3):353-66. doi: 10.2170/jjphysiol.27.353.

DOI:10.2170/jjphysiol.27.353

Abstract

The effects of catecholamines (adrenaline, noradrenaline and isoproterenol) on ionic conductance changes during the generation of action potentials of bullfrog sympathetic and spinal ganglion cells were studied with intracellular microelectrodes. In sympathetic ganglion cells, adrenaline (3X10(-5)-1X10(-3)M) reversibly decreased the peak amplitude and positive after-potential of action potentials, and prolonged the duration of spike potentials without changes in the resting membrane potential and conductance in the Ringer solution. The maximum rates of rise and fall of spike potentials were also decreased. The action of noradrenaline was similar to that of adrenaline, but isoproterenol did not show any effects. Adrenaline (3X10(-5)-3X10(-4)M) markedly depressed the peak amplitude and maximum rate of rise of both TEA-potential and Ca-potential produced either in TEA solution containing TTX or in the isotonic CaCl2 solution. Similar actions were observed with noradrenaline but not isoproterenol. In spinal ganglion cells, catecholamines did not show any effects of the action potentials in Ringer and TEA solutions. It was concluded that adrenaline inhibited the increases in Ca2+, K+ and Na+ conductances during the generation of action potentials of sympathetic ganglion cells.

摘要

用细胞内微电极研究了儿茶酚胺（肾上腺素、去甲肾上腺素和异丙肾上腺素）对牛蛙交感神经节和脊髓神经节细胞动作电位产生过程中离子电导变化的影响。在交感神经节细胞中，肾上腺素（3×10⁻⁵ - 1×10⁻³M）可逆地降低动作电位的峰值幅度和正后电位，并延长锋电位的持续时间，而在林格氏液中静息膜电位和电导无变化。锋电位的最大上升和下降速率也降低。去甲肾上腺素的作用与肾上腺素相似，但异丙肾上腺素无任何作用。肾上腺素（3×10⁻⁵ - 3×10⁻⁴M）显著降低在含TTX的TEA溶液或等渗CaCl₂溶液中产生的TEA电位和Ca电位的峰值幅度和最大上升速率。去甲肾上腺素也观察到类似作用，但异丙肾上腺素没有。在脊髓神经节细胞中，儿茶酚胺在林格氏液和TEA溶液中对动作电位无任何影响。得出的结论是，肾上腺素抑制交感神经节细胞动作电位产生过程中Ca²⁺、K⁺和Na⁺电导的增加。