Influência das variações hormonais no contato social de ratas com diferentes condições nociceptivas

• Ano de defesa: 2017
• Autor(a) principal: Santos, José Marcos Melo dos
• Orientador(a): Silva, Luís Felipe Souza da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Ciências Fisiológicas
• Palavras-chave em Português: Analgesia; Dor; Comportamento; Estro; Medição da dor; Fêmeas; Ciclo estral; Nocicepção; Empatia
• Palavras-chave em Inglês: Female; Estrous cycle; Empathy; Nociception
• Área do conhecimento CNPq: CIENCIAS BIOLOGICAS::FISIOLOGIA
• Link de acesso: https://ri.ufs.br/handle/riufs/6838

Pain can be defined as an unpleasant emotional and sensory experience associated with actual or potential tissue injury. About 70% of the individuals affected by chronic pain are female and the gonadal hormones play a decisive role in terms of sex differences and nociceptive responses. Studies suggest that rodents can recognize pain in co-specifics and expend active behaviors toward it. The main objective of the present study was to evaluate the influence of hormonal changes related to the estrous cycle on the social contact of rats during inflammatory pain and the effect of social contact on the nociceptive responses of female rats with inflammatory pain. Wistar female rats were used at 2 to 3 months of age. The project was composed of two experimental protocols. Experiment I evaluate the behavior of resident rats during exposure to cohabitants with inflammatory pain. It was composed of the following groups and experimental animals: Resident rats (RES), Control (CTRL), Formalin social contact (FCS) and saline (SAL). The three groups were repeated in different cycles stages, and three experiments were carried out where the residents are called Resident Estrous (RES / ES), Resident Ovariectomized (RES / OV) and Resident Proestrus (RES / PRO) All rats but ES and PRO residents underwent ovariectomy surgery. Experiment II was composed of the groups: Formalin Social Contact and the Formalin Isolate, which received the administration of formalin (1%) and was submitted to a 20min isolation period. After the 20 min of contact or isolation the nociceptive responses were evaluated for 40 minutes. The parameters used to evaluate the nociceptive responses were the lick time and the number of flinches. All groups were composed of n = 8. The results showed interaction between the phase the cycle versus treatment (p = 0.0013) for contact duration. In the case of the group of OV residents, (P <0.05) and with those residents in proestrus (p <0.001). In the experiment II, no difference was observed between the FCS and FI groups in groups composed of animals that had contact with ovariectomized or estrus residents. The group composed of animals that had contact with the proestrus residents showed analgesia during thirty minutes of the formalin test between 0 and 30 minutes of observation. The results suggest that rats recognize pain component in a cohabitant and direct active behaviors towards it, however the intensity and quality of this contact may vary according to the cycle. Regarding the nociceptive responses, it was observed that the social contact evoked through direct social behaviors was not enough to elicit analgesia, however aggressive behaviors on the part of the resident elicited an analgesia that may be based on the descending system through RVM with opioid character and being induced by stress.