title: The effects of centrally injected arachidonic acid on respiratory system: Involvement of cyclooxygenase to thromboxane signaling pathway.
abstract: Arachidonic acid (AA) is a polyunsaturated fatty acid that is present in the phospholipids of the cell membranes of the body and is abundant in the brain. Exogenously administered AA has been shown to affect brain metabolism and to exhibit cardiovascular and neuroendocrine actions. However, little is known regarding its respiratory actions and/or central mechanism of its respiratory effects. Therefore, the present study was designed to investigate the possible effects of centrally injected AA on respiratory system and the mediation of the central cyclooxygenase (COX) to thromboxane A2 (TXA2) signaling pathway on AA-induced respiratory effects in anaesthetized rats. Intracerebroventricular (i.c.v.) administration of AA induced dose- and time-dependent increase in tidal volume, respiratory rates and respiratory minute ventilation and also caused an increase in partial oxygen pressure (pO2) and decrease in partial carbon dioxide pressure (pCO2) in male anaesthetized Spraque Dawley rats. I.c.v. pretreatment with ibuprofen, a non-selective COX inhibitor, completely blocked the hyperventilation and blood gases changes induced by AA. In addition, central pretreatment with different doses of furegrelate, a TXA2 synthesis inhibitor, also partially prevented AA-evoked hyperventilation and blood gases effects. These data explicitly show that centrally administered AA induces hyperventilation with increasing pO2 and decreasing pCO2 levels which are mediated by the activation of central COX to TXA2 signaling pathway.
authors.affiliation: Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey.
authors.forename: Leman Gizem
authors.initials: LG
authors.lastname: Erkan
authors.affiliation: Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey.
authors.forename: Gokcen
authors.initials: G
authors.lastname: Guvenc
authors.affiliation: Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey.
authors.forename: Burcin
authors.initials: B
authors.lastname: Altinbas
authors.affiliation: Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey.
authors.forename: Nasir
authors.initials: N
authors.lastname: Niaz
authors.affiliation: Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey. Electronic address: mrtylcn75@gmail.com.
authors.forename: Murat
authors.initials: M
authors.lastname: Yalcin
mesh_terms: D000758:Anesthesia; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D001572:Benzofurans / Q000494:pharmacology; D002245:Carbon Dioxide / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007052:Ibuprofen / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D010100:Oxygen / Q000097:blood; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000187:drug effects; D012137:Respiratory System / Q000187:drug effects* / Q000201:enzymology*; D019141:Respiratory System Agents / Q000494:pharmacology; D013928:Thromboxane A2 / Q000378:metabolism*; D013990:Tidal Volume / Q000187:drug effects / Q000502:physiology; D013997:Time Factors
chemical_list: D001572:Benzofurans; D004791:Enzyme Inhibitors; D019141:Respiratory System Agents; D002245:Carbon Dioxide; D016718:Arachidonic Acid; D013928:Thromboxane A2; D011451:Prostaglandin-Endoperoxide Synthases; C039936:furegrelate; D010100:Oxygen; D007052:Ibuprofen
keywords: Arachidonic acid; Cyclooxygenase; Intracerebroventricular; Partial carbon dioxide pressure; Partial oxygen pressure; Respiratory Minute Ventilation; Respiratory rate; Thromboxane A2; Tidal volume