Background & Aims

5-Hydroxytryptamine (5-HT, serotonin) is a cell-derived vasoactive amine, mainly released by platelets (in humans), mast cells (in rodents) and endothelial cells. 5-HT receptor subtypes have been described in different tissues and demonstrated to be involved in painful and inflammatory conditions. Although 5-HT is implicated in the regulation of a number of physiological processes and their malfunctions, the exact sites and mechanisms of its action still remain under investigation. Previously, our results showed that 5-HT1, 5-HT2, 5-HT6 and 5-HT7 receptors are involved in peripheral nociception induced by 5-HT in different behavioural models in mice. Interestingly, 5-HT3 receptors may mediate antinociceptive effect under such experimental conditions. To support our previous findings, the aim of this study is to investigate the role played by 5-HT receptors in the peripheral nociceptive response by detecting 5-HT receptors in peripheral tissues of rats or mice.

Methods

Fragments from paw plantar surface were collected. 5-HT1B, 5-HT1D, 5-HT2A, 5-HT3 and 5-HT7 receptors expression and its mRNA were assessed by western blotting and qPCR techniques, respectively, in rats or mice peripheral tissues.

Results

Expression of 5-HT1B, 5-HT1D, 5-HT3 and 5-HT7 receptors were found in rats peripheral tissues. 5-HT1B, 5-HT1D, 5-HT2A, and 5-HT3 mRNA were found in dorsal root ganglia (DRG) samples, but not in paw tissues of mice.

Conclusions

The results suggest that different 5-HT receptors are expressed in peripheral tissues of rats or mice. Results can vary due to species differences or techniques applied. In previous behavioural experiments, we found that 5-HT receptors are involved in nociceptive response. Altogether, by the use of different antagonists and by pointing out its molecular targets, our results indicate that 5-HT and its receptors play an important role on peripheral features of nociception. Further investigation is needed to fully characterize such receptors involvement as well as to provide better understanding of 5-HT and other mediators role in peripheral nociceptive response.

References

1) Role of peripheral 5-HT1D, 5-HT3 and 5-HT7 receptors in the mechanical allodynia induced by serotonin in mice. Elias B Nascimento Jr, Thiago R L Romero, Marcela M G B Dutra, Bernd L Fiebich, Igor D G Duarte, Márcio M Coelho. Biomed Pharmacother. 2021 Mar:135:111210. doi: 10.1016/j.biopha.2020.111210. Epub 2021 Feb 1
2) Peripheral 5-HT1B and 5-HT2A receptors mediate the nociceptive response induced by 5-hydroxytryptamine in mice. Elias B Nascimento Jr 1, João Gabriel T Seniuk, Adriana M Godin, Wallace C Ferreira, Marcela B Dutra, Antônio Carlos P Oliveira, Leandro F S Bastos, Bernd L Fiebich, Márcio M Coelho. Pharmacol Biochem Behav. 2011 Oct;99(4):598-603. doi: 10.1016/j.pbb.2011.06.016. Epub 2011 Jun 16.

Presenting Author

Elias Nascimento Junior

Poster Authors

Elias Nascimento Junior

PhD

Delta do Parnaíba Federal University - UFDPar

Lead Author

Marcela Bini Dutra

UFMG

Lead Author

Bernd Fiebich PhD

Universitätsklinikum Freiburg

Lead Author

Marcio Coelho PhD

Federal University of Minas Gerais - UFMG

Lead Author

Topics

  • Mechanisms: Biological-Molecular and Cell Biology