Produção Nacional
Revisado por pares
Terpinen-4-ol: mechanisms of relaxation on rabbit duodenum
2005; Oxford University Press; Volume: 57; Issue: 4 Linguagem: Inglês
10.1211/0022357055696
ISSN2042-7158
AutoresNilberto Robson Falcão do Nascimento, José Henrique Leal‐Cardoso, Lucília M. A. Lessa, Jarbas S. Roriz‐Filho, Karina M.A. Cunha, Manassés Claudino Fonteles,
Tópico(s)Gastrointestinal motility and disorders
ResumoAbstract The effect of terpinen-4-ol was studied on rabbit duodenum in-vitro. Terpinen-4-ol induced relaxation of the basal tonus (IC50 170.2 (95% confidence interval, 175–204) μm) with a maximal relaxant response of 180.4 ± 3.9% (n = 6) of the contraction induced by 60 mm [K+]. The maximal relaxation induced in control conditions was not affected (P>0.05) by pretreatment of the tissues with phentolamine (50 μm) or propranolol (10 μm), Ng nitro-l-arginine methyl ester (L-NAME; 1 mm), 1H-(1,2,4)-oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 100 μm), hexamethonium (1 mm), tetrodotoxin (1 μm), the mixture charybdotoxin-apamin (1 μm), glibenclamide (10 μm), 4-aminopyridine (10 μm) or tetraethylammonium (100 μm). In addition, terpinen-4-ol completely relaxed tissues precontracted with 60 mm [K+] solutions (IC50 325.9 (245.1–433.1) μm) and also blocked (IC50 154.7 (117.7–191.7) μm) the phasic component of this contraction. At a concentration of 195 and 650 μm it reduced by 41.3 ± 3.4% and 75.4 ± 3.1%, respectively the maximal contractile response to Ca2+ in depolarized duodenum. Terpinen-4-ol completely blocked the component of carbachol-induced contraction, which was resistent to nifedipine (100 μm) pretreatment or to a Ca2+-free solution. These data show that terpinen-4-ol relaxes intestinal smooth muscle and suggest that this effect is myogenic in nature and depends on calcium antagonism.
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