Orexin A reverses propofol and thiopental induced cytoskeletal rearrangement in rat neurons
2014 (English)In: Journal of Physiology and Pharmacology, ISSN 0867-5910, Vol. 65, no 4, 531-541 p.Article in journal (Refereed) Published
Orexin A (OA) is an endogenous peptide regulating awakefulness, known to reduce anaesthesia in animals, but on cellular level its mechanisms to reverse anaesthetics are unknown. Primary cortical cell cultures from newborn rat brains are used and live cell light microscopy is performed to measure 1) neurite retraction after propofol, thiopental, barbituric acid and ketamine exposure and 2) the effect of OA application either before or after anaesthetics. Cytoskeletal reorganization is evaluated with fluorescence microscopy, protein changes are detected with Western blots and mass spectrometry is used to identify proteins after treatment with anaesthetics and/or OA. Adult rats are anaesthesized with propofol, and the cytoskeletal morphology is studied. Orexin A reverses and inhibits neurite retraction and actin ring formation induced by propofol and thiopental. No effect on retraction or actin rings was seen for ketamine (not active on gamma-aminobutiric acid (A) (GABA(A)) receptors), the non-anaesthetic barbituric acid, OA or solvents used. OA increases the tyrosine phosphorylation of a 50 kDa protein, identified as vimentin. Propofol induces an immediate granular appearance of vimentin, which OA reverses to a smooth distribution. Cytoskeletal morphology changes are also induced by propofol in vivo. All OA effects are blocked with an orexin receptor(1) (OX1) antagonist. We conclude that OA reverses the GABA(A) receptor mediated cellular effects of both propofol and thiopental in rat brain cells. The morphologic changes of actin and vimentin caused by propofol and thiopental, and the subsequent reversal by OA, deepens our understanding of the mechanisms of anaesthesia.
Place, publisher, year, edition, pages
Polish Physiological Society , 2014. Vol. 65, no 4, 531-541 p.
orexin A; anaesthesia; orexin receptor(1) antagonist; actin; cytoskeletal morphology; ketamine; vimentin; gamma-aminobutiric acid (A) receptor
IdentifiersURN: urn:nbn:se:liu:diva-112069ISI: 000343017300008PubMedID: 25179085ScopusID: 2-s2.0-84906882999OAI: oai:DiVA.org:liu-112069DiVA: diva2:763776
Funding Agencies|Ostergotland County Council research foundation; Henry and Ella Stahl Research Foundation; Valter and Gertrud Gryhlin Foundation; Linkoping Society of Medicine2014-11-172014-11-132015-10-02