Tetrodotoxin functions as a stress relieving substance in juvenile tiger puffer Takifugu rubripes
Tetrodotoxin functions as a stress relieving substance in juvenile tiger puffer Takifugu rubripes
复制标题
DOI：
10.1016/j.toxicon.2019.09.024
复制
发表时间：
2019-12-05
期刊：
影响因子：
2.8
通讯作者：
Sakakura, Yoshitaka
中科院分区：
文献类型：
--
作者：
Amano, Masafumi;Amiya, Noriko;Sakakura, Yoshitaka
我们测试了河豚毒素 (TTX) 是否可以作为河豚鱼的压力缓解物质。我们给孵化场饲养的无毒虎河豚红鳍东方鲀幼鱼口服 TTX，并与无毒幼鱼的效果进行比较，测量 TTX 对脑促肾上腺皮质激素释放激素 (CRH) mRNA 表达和血浆皮质醇水平的影响。首先，通过双标记免疫组织化学证实了CRH和促肾上腺皮质激素（ACTH）的相互联系。在下丘脑中检测到 CRH 免疫反应性 (ir) 细胞体，并观察到 CRH-ir 纤维投射到垂体远端头侧部的 ACTH-ir 细胞。接下来，在循环系统下向鱼喂食含 TTX 的饮食（2.35 小鼠单位（517 ng）/克饮食）或无毒饮食 28 天。 TTX 治疗组的标准身长和体重明显变大。尾鳍损失程度是竞争性相互作用程度的指标，高值表明鱼由于被其他个体咬伤而导致尾鳍损失较多，而 TTX 处理组的尾鳍损失程度明显较低。 TTX 治疗组大脑中相对 CRH mRNA 表达水平和血浆中皮质醇水平显着降低。这些结果表明，TTX 通过影响 CRH-ACTH-皮质醇轴并减少虎河豚幼鱼中的激动相互作用而发挥压力缓解物质的作用。
We tested whether tetrodotoxin (TTX) functions as a stress relieving substance in puffer fish. We orally administered TTX to the juveniles of hatchery-reared non-toxic tiger puffer Takifugu rubripes and measured the effects of TTX on brain corticotropin-releasing hormone (CRH) mRNA expression and plasma cortisol levels in comparison with effects in non-toxic juveniles. Firstly, the reciprocal connections of CRH and adrenocorticotropic hormone (ACTH) were confirmed by dual-label immunohistochemistry. CRH-immunoreactive (ir) cell bodies were detected in the hypothalamus and CRH-ir fibers were observed to project to ACTH-ir cells in the rostral pars distalis of the pituitary. Next, a TTX-containing diet (2.35 mouse units (517 ng)/g diet) or a non-toxic diet were fed to the fish for 28 days under a recirculating system. Standard length and body weight became significantly larger in the TTX-treated group. The degree of loss of the caudal fin, which is an indicator of the degree of agonistic interactions, where high values show a higher loss of caudal fin of a fish due to nipping by other individuals, was significantly lower in the TTX-treated group. Relative CRH mRNA expression levels in the brain and cortisol levels in the plasma were significantly lower in the TTX-treated group. These results indicate that TTX functions as a stress relieving substance by affecting the CRH-ACTH-cortisol axis and reducing agonistic interactions in tiger puffer juveniles.