{"title":"Fluoxetine antagonizes the acute response of LPS: Blocks K2P channels","authors":"Elizabeth R. Elliott, Robin L. Cooper","doi":"10.1016/j.cbpc.2024.110045","DOIUrl":null,"url":null,"abstract":"<div><div>The channels responsible for maintaining resting membrane potential are known as K2P (two-P-domain K<sup>+</sup> subunit) channels, a subset of which are known to be blocked by Fluoxetine. In this experiment, the compound's effects on the membrane potential were examined on muscles in larval <em>Drosophila</em> overexpressing a subtype of K2P channel (known in <em>Drosophila</em> as dORKA1 or ORKA1) and compared to larvae without overexpression. The compound was also observed in sequence and/or combination with a form of lipopolysaccharide (LPS) that transiently activates K2P channels. Different concentrations of Fluoxetine were tested, and it was also examined in cocktail with the LPS. At 25 μM Fluoxetine exposure, muscle in control larvae underwent depolarization, while muscles overexpressing K2P channels hyperpolarized; at 50 μM, however, much more variable responses were observed. The LPS caused hyperpolarization in both larval strains, but the effect was more transient in the Canton-S line than in the K2P overexpressors. Finally, LPS continued to cause hyperpolarization even in the presence of Fluoxetine, while Fluoxetine quickly depolarized the muscle during exposure to LPS. The cocktail showed a smaller effect on muscles overexpressing ORKA1 as compared to the controls, indicating that Fluoxetine does not block the ORKA1 subtype. This study is significant because it demonstrates how overexpression of K2P channels alters membrane response to LPS and Fluoxetine exposure.</div></div>","PeriodicalId":10602,"journal":{"name":"Comparative Biochemistry and Physiology C-toxicology & Pharmacology","volume":"287 ","pages":"Article 110045"},"PeriodicalIF":3.9000,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Comparative Biochemistry and Physiology C-toxicology & Pharmacology","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1532045624002138","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The channels responsible for maintaining resting membrane potential are known as K2P (two-P-domain K+ subunit) channels, a subset of which are known to be blocked by Fluoxetine. In this experiment, the compound's effects on the membrane potential were examined on muscles in larval Drosophila overexpressing a subtype of K2P channel (known in Drosophila as dORKA1 or ORKA1) and compared to larvae without overexpression. The compound was also observed in sequence and/or combination with a form of lipopolysaccharide (LPS) that transiently activates K2P channels. Different concentrations of Fluoxetine were tested, and it was also examined in cocktail with the LPS. At 25 μM Fluoxetine exposure, muscle in control larvae underwent depolarization, while muscles overexpressing K2P channels hyperpolarized; at 50 μM, however, much more variable responses were observed. The LPS caused hyperpolarization in both larval strains, but the effect was more transient in the Canton-S line than in the K2P overexpressors. Finally, LPS continued to cause hyperpolarization even in the presence of Fluoxetine, while Fluoxetine quickly depolarized the muscle during exposure to LPS. The cocktail showed a smaller effect on muscles overexpressing ORKA1 as compared to the controls, indicating that Fluoxetine does not block the ORKA1 subtype. This study is significant because it demonstrates how overexpression of K2P channels alters membrane response to LPS and Fluoxetine exposure.
期刊介绍:
Part C: Toxicology and Pharmacology. This journal is concerned with chemical and drug action at different levels of organization, biotransformation of xenobiotics, mechanisms of toxicity, including reactive oxygen species and carcinogenesis, endocrine disruptors, natural products chemistry, and signal transduction with a molecular approach to these fields.