Casillas-Espinosa Pablo Miguel, Hicks Ashleigh, Jeffreys Amy, Snutch Terrance P, O'Brien Terence J, Powell Kim L
The Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia.
Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada.
PLoS One. 2015 Aug 14;10(8):e0130012. doi: 10.1371/journal.pone.0130012. eCollection 2015.
Temporal lobe epilepsy (TLE) is the most common form of drug resistant epilepsy. Current treatment is symptomatic, suppressing seizures, but has no disease modifying effect on epileptogenesis. We examined the effects of Z944, a potent T-type calcium channel antagonist, as an anti-seizure agent and against the progression of kindling in the amygdala kindling model of TLE. The anti-seizure efficacy of Z944 (5mg/kg, 10mg/kg, 30mg/kg and 100mg/kg) was assessed in fully kindled rats (5 class V seizures) as compared to vehicle, ethosuximide (ETX, 100mg/kg) and carbamazepine (30mg/kg). Each animal received the seven treatments in a randomised manner. Seizure class and duration elicited by six post-drug stimulations was determined. To investigate for effects in delaying the progression of kindling, naive animals received Z944 (30mg/kg), ETX (100mg/kg) or vehicle 30-minutes prior to each kindling stimulation up to a maximum of 30 stimulations, with seizure class and duration recorded after each stimulation. At the completion of drug treatment, CaV3.1, CaV3.2 and CaV3.3 mRNA expression levels were assessed in the hippocampus and amygdala using qPCR. Z944 was not effective at suppressing seizures in fully kindled rats compared to vehicle. Animals receiving Z944 required significantly more stimulations to evoke a class III (p<0.05), IV (p<0.01) or V (p<0.0001) seizure, and to reach a fully kindled state (p<0.01), than animals receiving vehicle. There was no significant difference in the mRNA expression of the T-type Ca2+ channels in the hippocampus or amygdala. Our results show that selectively targeting T-type Ca2+ channels with Z944 inhibits the progression of amygdala kindling. This could be a potential for a new therapeutic intervention to mitigate the development and progression of epilepsy.
颞叶癫痫(TLE)是药物难治性癫痫最常见的形式。目前的治疗只是对症治疗,可抑制癫痫发作,但对癫痫发生没有疾病修饰作用。我们研究了强效T型钙通道拮抗剂Z944作为抗癫痫药物以及在TLE杏仁核点燃模型中对抗点燃进展的作用。与赋形剂、乙琥胺(ETX,100mg/kg)和卡马西平(30mg/kg)相比,评估了Z944(5mg/kg、10mg/kg、30mg/kg和100mg/kg)在完全点燃大鼠(5级V型发作)中的抗癫痫疗效。每只动物以随机方式接受这七种治疗。确定药物刺激后六次引发的癫痫发作等级和持续时间。为了研究延迟点燃进展的作用,未点燃的动物在每次点燃刺激前30分钟接受Z944(30mg/kg)、ETX(100mg/kg)或赋形剂,最多进行30次刺激,每次刺激后记录癫痫发作等级和持续时间。药物治疗结束时,使用qPCR评估海马体和杏仁核中CaV3.1、CaV3.2和CaV3.3 mRNA表达水平。与赋形剂相比,Z944在抑制完全点燃大鼠的癫痫发作方面无效。与接受赋形剂的动物相比,接受Z944的动物诱发III级(p<0.05)、IV级(p<0.01)或V级(p<0.0001)癫痫发作以及达到完全点燃状态(p<0.01)所需的刺激次数明显更多。海马体或杏仁核中T型Ca2+通道的mRNA表达没有显著差异。我们的结果表明,用Z944选择性靶向T型Ca2+通道可抑制杏仁核点燃的进展。这可能是减轻癫痫发展和进展的一种新治疗干预措施的潜力。