Participation of potassium channels in the antinociceptive effect of docosahexaenoic acid in the rat formalin test

• Published in: European journal of pharmacology 2016-12, Vol.793, p.95-100
• Main Authors: Landa-Juárez, Arizai Yolia, Ortiz, Mario I., Castañeda-Hernández, Gilberto, Chávez-Piña, Aracely Evangelina
• Format: Article
• Language: English
• Subjects: Analgesics - pharmacology; Animals; Docosahexaenoic acid; Docosahexaenoic Acids - pharmacology; Dose-Response Relationship, Drug; Female; Formaldehyde - pharmacology; Nociception; Potassium Channel Blockers - pharmacology; Potassium channels; Potassium Channels - metabolism; Rat formalin test; Rats; Rats, Wistar
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/j.ejphar.2016.11.004

Docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid (PUFA) that has shown gastroprotective, cardioprotective, neuroprotective, anti-inflammatory and antinociceptive effects in different models. However, its action mechanism is still not well-defined. Reports indicate that some PUFAs regulate potassium (K+) channels in ventricular myocytes of rodents. As a result, the aim of this study was to evaluate the probable participation of K+ channels in the antinociceptive effect of DHA. The rat paw 1% formalin test was used to assess nociception and antinociception. Fifty microliters of formalin solution were administered subcutaneously in the paw, and the number of flinches were quantified. Rats were treated with local peripheral administration of DHA (100–1778µg/paw) or diclofenac (10–300µg/paw). The antinociception of DHA was evaluated with and without the local pretreatment of K+ channel blockers. DHA and diclofenac produced dose-dependent antinociceptive effects during the second phase (P