Ameri A
Department of Pharmacy and Pharmacology of Natural Compounds, University of Ulm, Germany.
Eur J Pharmacol. 1998 Jan 26;342(2-3):183-91. doi: 10.1016/s0014-2999(97)01498-2.
The aim of the present study was to investigate if the plant alkaloid, mesaconitine, which has been reported to have antinociceptive effects via stimulation of the noradrenergic system, inhibits epileptiform field potentials. The experiments were performed as extracellular recordings on rat hippocampal slices. Epileptiform activity was induced by omission of Mg2+ from the bathing medium or by addition of bicuculline and stimulus-evoked population bursts were recorded in the CA1 region. Spontaneous epileptiform activity was elicited by perfusing a nominally Mg2+-free bathing medium with high K+ concentration (5 mM). Both stimulus-triggered and spontaneous epileptiform activity was attenuated in a concentration-dependent manner by mesaconitine (30 nM-1 microM). The inhibitory effect was rather variable in appearance when lower concentrations (30 and 100 nM) of mesaconitine were applied. Pretreatment of the slices with the alpha-adrenoceptor antagonist yohimbine (1 microM) prevented the effect of mesaconitine. It is concluded that the inhibitory action of mesaconitine at low concentration is mediated via alpha-adrenoceptors.
本研究的目的是调查据报道通过刺激去甲肾上腺素能系统具有抗伤害感受作用的植物生物碱中乌头碱是否抑制癫痫样场电位。实验在大鼠海马切片上进行细胞外记录。通过从浴液中省略Mg2+或添加荷包牡丹碱诱导癫痫样活动，并在CA1区域记录刺激诱发的群体爆发。通过用高钾浓度（5 mM）灌注名义上无Mg2+的浴液来引发自发性癫痫样活动。中乌头碱（30 nM - 1 microM）以浓度依赖性方式减弱刺激触发的和自发性癫痫样活动。当应用较低浓度（30和100 nM）的中乌头碱时，抑制作用在外观上相当多变。用α-肾上腺素能受体拮抗剂育亨宾（1 microM）预处理切片可防止中乌头碱的作用。得出的结论是，低浓度中乌头碱的抑制作用是通过α-肾上腺素能受体介导的。
