Siebel Anna Maria, Menezes Fabiano Peres, Capiotti Katiucia Marques, Kist Luiza Wilges, da Costa Schaefer Isabel, Frantz Juliana Zanetti, Bogo Maurício Reis, Da Silva Rosane Souza, Bonan Carla Denise
1 Laboratório de Neuroquímica e Psicofarmacologia, Departamento de Biologia Celular e Molecular, Programa de Pós-Graduação em Biologia Celular e Molecular, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul , Porto Alegre, Brazil .
Zebrafish. 2015 Apr;12(2):127-36. doi: 10.1089/zeb.2014.1004. Epub 2015 Jan 5.
Adenosine is a well-known endogenous modulator of neuronal excitability with anticonvulsant properties. Thus, the modulation exerted by adenosine might be an effective tool to control seizures. In this study, we investigated the effects of drugs that are able to modulate adenosinergic signaling on pentylenetetrazole (PTZ)-induced seizures in adult zebrafish. The adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) decreased the latency to the onset of the tonic-clonic seizure stage. The adenosine A1 receptor agonist cyclopentyladenosine (CPA) increased the latency to reach the tonic-clonic seizure stage. Both the adenosine A2A receptor agonist and antagonist, CGS 21680 and ZM 241385, respectively, did not promote changes in seizure parameters. Pretreatment with the ecto-5'nucleotidase inhibitor adenosine 5'-(α,β-methylene) diphosphate (AMPCP) decreased the latency to the onset of the tonic-clonic seizure stage. However, when pretreated with the adenosine deaminase (ADA) inhibitor, erythro-9-(2-hydroxy-3-nonyl)-adenine (EHNA), or with the nucleoside transporter (NT) inhibitors, dipyridamole and S-(4-Nitrobenzyl)-6-thioinosine (NBTI), animals showed longer latency to reach the tonic-clonic seizure status. Finally, our molecular analysis of the c-fos gene expression corroborates these behavioral results. Our findings indicate that the activation of adenosine A1 receptors is an important mechanism to control the development of seizures in zebrafish. Furthermore, the actions of ecto-5'-nucleotidase, ADA, and NTs are directly involved in the control of extracellular adenosine levels and have an important role in the development of seizure episodes in zebrafish.
腺苷是一种众所周知的具有抗惊厥特性的内源性神经元兴奋性调节剂。因此，腺苷所发挥的调节作用可能是控制癫痫发作的一种有效手段。在本研究中，我们调查了能够调节腺苷能信号传导的药物对成年斑马鱼戊四氮（PTZ）诱导的癫痫发作的影响。腺苷A1受体拮抗剂8-环戊基-1,3-二丙基黄嘌呤（DPCPX）缩短了强直-阵挛性癫痫发作阶段开始的潜伏期。腺苷A1受体激动剂环戊腺苷（CPA）延长了达到强直-阵挛性癫痫发作阶段的潜伏期。腺苷A2A受体激动剂和拮抗剂，即CGS 21680和ZM 241385，均未引起癫痫发作参数的变化。用胞外5'-核苷酸酶抑制剂腺苷5'-(α,β-亚甲基)二磷酸（AMPCP）预处理可缩短强直-阵挛性癫痫发作阶段开始的潜伏期。然而，当用腺苷脱氨酶（ADA）抑制剂erythro-9-(2-羟基-3-壬基)-腺嘌呤（EHNA）或核苷转运体（NT）抑制剂双嘧达莫和S-(4-硝基苄基)-6-硫代肌苷（NBTI）预处理时，动物达到强直-阵挛性癫痫发作状态的潜伏期延长。最后，我们对c-fos基因表达的分子分析证实了这些行为学结果。我们的研究结果表明，腺苷A1受体的激活是控制斑马鱼癫痫发作发展的重要机制。此外，胞外5'-核苷酸酶、ADA和NTs的作用直接参与细胞外腺苷水平的控制，并在斑马鱼癫痫发作事件的发展中起重要作用。
