Sex differences in sleep pattern of rats in an experimental model of osteoarthritis

Autor(es)

Silva, Andressa ^[1] ; Araujo, Paula ^[1] ; Zager, Adriano ^[1] ; Tufik, Sergio ^[1] ; Andersen, Monica Levy ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Psicobiol, Escola Paulista Med UNIFESP EPM, BR-04024002 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: EUROPEAN JOURNAL OF PAIN; v. 15, n. 6, p. 545-553, JUL 2011.
• Citações Web of Science: 9

Resumo

Background: Osteoarthritis (OA) is a major healthcare burden with increasing incidence, and is characterised by the degeneration of articular cartilage. OA is associated with chronic pain and sleep disturbance. Objective: The current study examined and compared the long-term effects of chronic articular pain on sleep patterns between female and male rats in an experimental model of OA. Methods: Rats were implanted with electrodes for electrocorticography and electromyography and assigned to control, sham or OA groups. OA was induced by the intra-articular administration of (2 mg) monosodium iodoacetate into the left knee joint in male and female rats (at estrus and diestrus phases). Results: Sleep was monitored at days 1, 10, 15, 20 and 28 after iodoacetate injection during light and dark periods. The results showed that the overall sleep architecture changed in both sexes. These alterations occurred during the light and dark periods, began on D1 and persisted until the end of the study. OA rats, regardless of sex, showed a fragmented sleep pattern with reduced sleep efficiency, slow-wave sleep and paradoxical sleep, and fewer paradoxical sleep bouts. However, the males showed lower sleep efficiency and reduced slow-wave sleep compared to females during the dark period. Additionally, OA affected the hormonal levels in male rats, as testosterone levels were reduced in comparison to the control and sham groups. In females, progesterone and estradiol remained unchanged throughout the study. Conclusions: Our results suggest that the chronic model of OA influenced the sleep patterns in both sexes. However, males appeared to be more affected. (C) 2010 Published by Elsevier Ltd. on behalf of European Federation of International Association for the Study of Pain Chapters. (AU)

• Processo FAPESP: 07/56620-6 - Efeitos da privação de sono paradoxal na sensibilidade dolorosa em ratos machos e fêmeas
• Beneficiário: Andressa da Silva de Mello
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 06/58275-1 - Efeitos da privação de sono na resposta ao lipopolissacarídeo bacteriano: aspectos comportamentais, neuroquímicos e imunológicos em camundongos
• Beneficiário: Adriano Zager
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 10/50130-0 - Estudo do sistema nociceptivo de camundongos submetidos a restrição de sono durante o período neonatal
• Beneficiário: Paula Cristina Alves Araújo
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 98/14303-3 - Center for Sleep Studies
• Beneficiário: Sergio Tufik
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs