Role of hydrogen sulfide in orofacial nociception in rats

• Grant number: 12/12634-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2012
• End date: October 31, 2013
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Christie Ramos Andrade Leite Panissi
• Grantee: Leopoldo Ulian Azevedo
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The gaseous signaling molecule studies made great progress over the past decades. Hydrogen sulfide (or hydrogen sulfide) has been considered a neuromodulator/neurotransmitter gas, similar to nitric oxide and carbon monoxide. The H2S was first demonstrated as a signaling molecule, possibly neuromodulatory function. Although the release mechanisms are not yet completely clarified, they can be produced by enzymatic reactions and released immediately after their production. The primary pathway for the production of H2S has the amino acid cysteine as a precursor. Three enzymes are involved in this pathway: Cystathionine beta-synthase (CBS), Cystathionine gamma-lyase (CSE), and 3-mercaptopiruvato sulfurtransferase (3MST). CSE is distributed predominantly in peripheral tissues, in spite of this, there are reports of expression in the brain CSE in a ratio of 30 times smaller than the CBS. Some evidence points to a pro-nociceptive effect of H2S. This work will be assessed if the hydrogen sulfide is involved in orofacial nociceptive response using the orofacial formalin test in rats, considering: to evaluate whether pretreatment with different concentrations of inhibitor Cystathionine gamma-lyase (CSE) promotes change in nociceptive behavior observed in the orofacial formalin test in rats to evaluate whether administration of a donor of H2S, NaHS, in different concentrations, change the nociceptive response of orofacial formalin test in rats. To study the involvement of the local peripheral H2S in nociception, drugs will be injected at set intervals before the formalin test.(AU)