Avaliação do limiar nociceptivo de animais adultos nascidos a termo ou pré-termo submetidos a estímulo pinprick no período neonatal

• Ano de defesa: 2019
• Autor(a) principal: Carvalho, Ravena Carolina De
• Orientador(a): Silva, Marcelo Lourenço Da
• Banca de defesa: Medeiros, Priscila De, Reis, Luciana Maria Dos, Almeida, Marcos Dos Santos De, Alves, Fernando Henrique Ferrari
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Alfenas
• Programa de Pós-Graduação: Programa de Pós-Graduação em Biociências Aplicada à Saúde
• Departamento: Instituto de Ciências Biomédicas
• País: Brasil
• Palavras-chave em Português: Dor; Triagem Neonatal; Terapia Intensiva Neonatal; Recém-Nascido Prematuro; Prematuro
• Área do conhecimento CNPq: CIENCIAS DA SAUDE::MEDICINA
• Link de acesso: https://repositorio.unifal-mg.edu.br/handle/123456789/1346

Background and aims: Newborn infants are vulnerable to procedural stress and pain exposure on the first weeks of life that represents a critical period for the development of nociceptive, sensory, emotional, and social functions. We evaluated the nociceptive behavior of adult male and female rats that were submitted to nociceptive experience in the neonatal period and the maternal behavior in the postnatal period. Methods: The animals were submitted to repetitive needle pricking from the second to the fifteenth postnatal day (PND 2–15). Maternal behavior and litter weight were evaluated during this period. Mechanical sensitivity to pain was assessed in offsprings during the adulthood by exposing them to inflammatory stimuli, including formalin test or the Freund’s complete adjuvant (CFA) injection followed by the electronic von Frey test at 0, 3, 6 and 24 h later. Results: Maternal behavior and litter weight were not altered by pinprick stimuli during PND 2–15 in both groups. Additionally, pinprick stimulation reduced the paw withdrawal threshold in CFA-injected animals compared to control in preterm and term offspring. In the formalin test, there was a difference between the genders in term offspring but preterm there wasn’t difference. Female rats are statically more sensitive to formalin stimulation and showed an increased licking time in both the first and second phases and increased number of flinches in second phase. Conclusions: Experiencing early life repetitive pain exposure increased inflammatory pain sensitivity in adult offspring rats and female rats are more sensitive to chemical stimulation. Implications: Future investigations of the mechanisms involved in this effect may contribute to the improvement of the understanding of inflammatory pain sensitivity differences.