TRPM8 Channel Activation Induced by Monoterpenoid Rotundifolone Underlies Mesenteric Artery Relaxation

PLoS One. 2015 Nov 23;10(11):e0143171. doi: 10.1371/journal.pone.0143171. eCollection 2015.

Abstract

In this study, our aims were to investigate transient receptor potential melastatin-8 channels (TRPM8) involvement in rotundifolone induced relaxation in the mesenteric artery and to increase the understanding of the role of these thermosensitive TRP channels in vascular tissue. Thus, message and protein levels of TRPM8 were measured by semi-quantitative PCR and western blotting in superior mesenteric arteries from 12 week-old Spague-Dawley (SD) rats. Isometric tension recordings evaluated the relaxant response in mesenteric rings were also performed. Additionally, the intracellular Ca2+ changes in mesenteric artery myocytes were measured using confocal microscopy. Using PCR and western blotting, both TRPM8 channel mRNA and protein expression was measured in SD rat mesenteric artery. Rotundifolone and menthol induced relaxation in the isolated superior mesenteric artery from SD rats and improved the relaxant response induced by cool temperatures. Also, this monoterpene induced an increase in transient intracellular Ca2+. These responses were significantly attenuated by pretreatment with capsazepine or BCTC, both TRPM8 channels blockers. The response induced by rotundifolone was not significantly attenuated by ruthenium red, a non-selective TRP channels blocker, or following capsaicin-mediated desensitization of TRPV1. Our findings suggest that rotundifolone induces relaxation by activating TRPM8 channels in rat superior mesenteric artery, more selectively than menthol, the classic TRPM8 agonist, and TRPM8 channels participates in vasodilatory pathways in isolated rat mesenteric arteries.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Calcium / metabolism
  • Calcium Signaling / drug effects
  • Capsaicin / pharmacology
  • Cold Temperature
  • Cytosol / metabolism
  • In Vitro Techniques
  • Ion Channel Gating / drug effects*
  • Male
  • Menthol / pharmacology
  • Mesenteric Arteries / drug effects
  • Mesenteric Arteries / physiology*
  • Monoterpenes / pharmacology*
  • Pyrazines / metabolism
  • Pyridines / metabolism
  • Rats, Sprague-Dawley
  • Real-Time Polymerase Chain Reaction
  • Ruthenium Red / metabolism
  • TRPM Cation Channels / metabolism*
  • TRPV Cation Channels / metabolism
  • Vasodilation / drug effects
  • Vasodilation / physiology*

Substances

  • Monoterpenes
  • N-(4-tert-butylphenyl)-4-(3-chloropyridin-2-yl)tetrahydropyrazine-1(2H)-carboxamide
  • Pyrazines
  • Pyridines
  • TRPM Cation Channels
  • TRPV Cation Channels
  • Trpm8 protein, rat
  • Trpv1 protein, rat
  • Ruthenium Red
  • Menthol
  • rotundifolone
  • Capsaicin
  • Calcium

Grants and funding

DFS was supported by Fundação de Amparo à pesquisa do estado da Bahia (FAPESB—http://www.fapesb.ba.gov.br). JSC was supported by Fundação de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG – www.fapemig.br). IAM and MFL were supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq—http://www.cnpq.br). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.