An ethyl acetate fraction obtained from a Southern Brazilian red wine relaxes rat mesenteric arterial bed through hyperpolarization and NO-cGMP pathway.
A number of studies suggest that moderate consumption of red wine may be more effective than other alcoholic beverages in decreasing the risk of coronary heart disease (CAD). In this study, we investigated the effect of a crude extract (CE), as well as an ethyl acetate fraction (EAF) obtained from a Brazilian red wine in the mesenteric arterial bed (MAB) from rats. Our results showed that after the tonus of MAB was increased with phenylephrine (PE), increasing concentrations of CE induced a concentration-dependent relaxation; moreover, EAF was more potent in relaxing the MAB when compared with CE. In vessels depolarized with KCl (80 mM) or treated with the Na(+)/K(+)-ATPase pump inhibitor, ouabain (OUA; 100 microM), or with the K(+) channel blockers: barium (BaCl(2), 100 microM) and tetraethylammonium (TEA; 500 microM), the effect of EAF was significantly reduced. However, this effect was not altered by the ATP-dependent K(+) (K(ATP)) channel blocker, glibenclamide (GLI; 100 microM) as well as Charybdotoxin (ChTx 10 nM), a nonselective inhibitor of K(Ca) channels of large and intermediate conductance plus Apamin (Apamin 100 nM), a specific inhibitor of K(Ca) channels of small conductance. The residual vasodilator effect of EAF observed in vessels pretreated with L-NOARG (100 microM), 1H-[1,2,4,] oxadiazolo[4,3-alfa]quinoxalin, ODQ (10 microM) or KCl (80 mM), given separately, was reduced by the administration of KCl (40 mM) plus L-NOARG (100 microM). The present study demonstrates that the vasodilator effect of EAF is partially dependent upon membrane hyperpolarization in combination with nitric oxide (NO) release.
Schuldt
Elke Zuleika
EZ
Departamento de Farmacologia, CCB, Universidade Federal de Santa Catarina, Coordenadoria Especial de Farmacologia/BLOCO D, Campus Universitario Trinidade-Florianópolis-SC, CEP: 88049-900, CP 476, Brazil. elkeschuldt@pop.com.br
Bet
Angela Cristina
AC
Hort
Mariana Appel
MA
Ianssen
Carla
C
Maraschin
Marcelo
M
Ckless
Karina
K
Ribeiro-do-Valle
Rosa Maria
RM
D000085:Acetates / Q000737:chemistry*; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001685:Biological Factors / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001938:Brazil; D006152:Cyclic GMP / Q000502:physiology*; D004594:Electrophysiology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009569:Nitric Oxide / Q000737:chemistry*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052250:Nitric Oxide Synthase Type III; D019335:Nitroarginine / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors; D012997:Solvents; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology; D014920:Wine / Q000032:analysis*
D000085:Acetates; D001685:Biological Factors; D010936:Plant Extracts; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D012997:Solvents; D014665:Vasodilator Agents; C067410:endothelium-dependent hyperpolarization factor; D019335:Nitroarginine; D009569:Nitric Oxide; D011189:Potassium Chloride; C007650:ethyl acetate; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D000254:Sodium-Potassium-Exchanging ATPase; D006152:Cyclic GMP; D000109:Acetylcholine