The serotonin transporter and nonselective transporters are involved in peripheral serotonin uptake in the Gulf toadfish, Opsanus beta
The serotonin transporter and nonselective transporters are involved in peripheral serotonin uptake in the Gulf toadfish, Opsanus beta
复制标题
血清素转运蛋白和非选择性转运蛋白参与海湾蟾蜍 Opsanus beta 的外周血清素摄取
DOI：
10.1152/ajpregu.00137.2018
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
McDonald, M. Danielle
中科院分区：
文献类型：
--
作者：
Amador, Molly H.;McDonald, M. Danielle
在哺乳动物中，循环血清素 [5-羟色胺 (5-HT)] 通过 5-HT 转运蛋白 (SERT) 被血小板隔离，以防止这种有效的信号分子发出意外的信号。硬骨鱼似乎缺乏类似的循环储存池，尽管 5-HT 对硬骨鱼的不同影响可能需要采用替代的严格调节方法，例如通过外周组织吸收。本研究利用5-HT放射性示踪剂探讨了海湾蟾蜍Opsanus beta外周组织对5-HT的摄取能力，并阐明了5-HT及其代谢物的主要排泄途径。 SERT 和其他转运蛋白的药理抑制能够评估外周 5-HT 摄取和排泄的 SERT 依赖性。结果表明，心房、心室和鳃对 5-HT 的快速而大量的吸收至少部分依赖于 SERT。结果还支持部分血脑屏障的存在，尽管血浆 5-HT 浓度存在波动，但该屏障可阻止大脑 5-HT 含量的快速变化。肾脏途径似乎是 5-HT 及其代谢物在较短时间范围内（最多约 30 分钟）的主要排泄途径，但在几个小时内肝脏排泄量很大。 SERT 抑制最终减少了 5-HT 及其代谢物通过尿路、胆道和/或肠道途径的排泄。此外，不能排除5-HT及其代谢物的鳃排泄。总之，这项研究揭示了蟾蜍的心脏和鳃在调节循环 5-HT 中发挥着积极作用，并为这种硬骨鱼外周 5-HT 的控制提供了重要的见解。
In mammals, circulating serotonin [5-hydroxytryptamine (5-HT)] is sequestered by platelets via the 5-HT transporter (SERT) to prevent unintended signaling by this potent signaling molecule. Teleost fish appear to lack a similar circulating storage pool, although the diverse effects of 5-HT in teleosts likely necessitate an alternative method of tight regulation, such as uptake by peripheral tissues. Here, a 5-HT radiotracer was used to explore the 5-HT uptake capacity of peripheral tissues in the Gulf toadfish,Opsanus beta, and to elucidate the primary excretion routes of 5-HT and its metabolites. Pharmacological inhibition of SERT and other transporters enabled assessment of the SERT dependence of peripheral 5-HT uptake and excretion. The results indicated a rapid and substantial uptake of 5-HT by the heart atrium, heart ventricle, and gill that was at least partly SERT dependent. The results also supported the presence of a partial blood-brain barrier that prevented rapid changes in brain 5-HT content despite fluctuating plasma 5-HT concentrations. The renal pathway appeared to be the dominant excretory route for 5-HT and its metabolites over shorter time frames (up to ~30 min), but hepatic excretion was substantial over several hours. SERT inhibition ultimately reduced the excretion of 5-HT and its metabolites by urinary, biliary, and/or intestinal pathways. In addition, branchial excretion of 5-HT and its metabolites could not be ruled out. In summary, this study reveals that the toadfish heart and gill play active roles in regulating circulating 5-HT and yields important insights into the control of peripheral 5-HT in this teleost fish.