Data/hora: 07/06/2024 15:37:00

Provedor de dados: 	Brazilian Journal of Medical and Biological Research	
País: 	Brazil	
Título: 	Chronic intrathecal cannulation enhances nociceptive responses in rats	
Autores: 	Almeida,F.R.C.; Schivo,I.R.S.; Lorenzetti,B.B.; Ferreira,S.H.	
Data: 	2000-08-01	
Ano: 	2000	
Palavras-chave: 	Hyperalgesia; Spinal sensitization; Intrathecal cannulation; Nociceptive response; Inflammation.	
Resumo: 	The influence of a chronically implanted spinal cannula on the nociceptive response induced by mechanical, chemical or thermal stimuli was evaluated. The hyperalgesia in response to mechanical stimulation induced by carrageenin or prostaglandin E2 (PGE2) was significantly increased in cannulated (Cn) rats, compared with naive (Nv) or sham-operated (Sh) rats. Only Cn animals presented an enhanced nociceptive response in the first phase of the formalin test when low doses were used (0.3 and 1%). The withdrawal latency to thermal stimulation of a paw inflamed by carrageenin was significantly reduced in Cn rats but not in Nv or Sh rats. In contrast to Nv and Sh rats, injection in Cn animals of a standard non-steroid anti-inflammatory drug, indomethacin, either intraperitoneally or into the spinal cord via an implanted cannula or by direct puncture of the intrathecal space significantly blocked the intensity of the hyperalgesia induced by PGE2. Cannulated animals treated with indomethacin also showed a significant inhibition of second phase formalin-induced paw flinches. Histopathological analysis of the spinal cord showed an increased frequency of mononuclear inflammatory cells in the Cn groups. Thus, the presence of a chronically implanted cannula seems to cause nociceptive spinal sensitization to mechanical, chemical and thermal stimulation, which can be blocked by indomethacin, thus suggesting that it may result from the spinal release of prostaglandins due to an ongoing mild inflammation.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000800011	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2000000800011	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.33 n.8 2000	
Fonte: 	info:eu-repo/semantics/openAccess