%0 Journal Article
%T Participation of the NO/cGMP/K+ATP pathway in the antinociception induced by Walker tumor bearing in rats
%A Barbosa
%A A.L.R.
%A Pinheiro
%A C.A.
%A Oliveira
%A G.J.
%A Torres
%A J.N.L.
%A Moraes
%A M.O.
%A Ribeiro
%A R.A.
%A Vale
%A M.L.
%A Souza
%A M.H.L.P.
%J Brazilian Journal of Medical and Biological Research
%D 2012
%I Associa??o Brasileira de Divulga??o Cient¨ªfica
%R 10.1590/S0100-879X2012007500047
%X implantation of walker 256 tumor decreases acute systemic inflammation in rats. inflammatory hyperalgesia is one of the most important events of acute inflammation. the l-arginine/no/cgmp/k+atp pathway has been proposed as the mechanism of peripheral antinociception mediated by several drugs and physical exercise. the objective of this study was to investigate a possible involvement of the no/cgmp/k+atp pathway in antinociception induced in walker 256 tumor-bearing male wistar rats (180-220 g). the groups consisted of 5-6 animals. mechanical inflammatory hypernociception was evaluated using an electronic version of the von frey test. walker tumor (4th and 7th day post-implantation) reduced prostaglandin e2- (pge2, 400 ng/paw; 50 ¦Ìl; intraplantar injection) and carrageenan-induced hypernociception (500 ¦Ìg/paw; 100 ¦Ìl; intraplantar injection). walker tumor-induced analgesia was reversed (99.3% for carrageenan and 77.2% for pge2) by a selective inhibitor of nitric oxide synthase (l-name; 90 mg/kg, ip) and l-arginine (200 mg/kg, ip), which prevented (80% for carrageenan and 65% for pge2) the effect of l-name. treatment with the soluble guanylyl cyclase inhibitor odq (100% for carrageenan and 95% for pge2; 8 ¦Ìg/paw) and the atp-sensitive k+ channel (katp) blocker glibenclamide (87.5% for carrageenan and 100% for pge2; 160 ¦Ìg/paw) reversed the antinociceptive effect of tumor bearing in a statistically significant manner (p < 0.05). the present study confirmed an intrinsic peripheral antinociceptive effect of walker tumor bearing in rats. this antinociceptive effect seemed to be mediated by activation of the no/cgmp pathway followed by the opening of katp channels.
%K walker 246 tumor-bearing rats
%K hypernociception
%K nitric oxide
%K carrageenan.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0100-879X2012000600009&lng=en&nrm=iso&tlng=en