title: Effect of wine polyphenol resveratrol on the contractions elicited electrically or by norepinephrine in the rat portal vein.
abstract: We investigated the effects of resveratrol on rat portal vein (RPV) contractility without endothelium. Contractions were produced by electrical field stimulation of perivascular nerves (EFS), norepinephrine (NE), adenosine 5'-triphosphate (ATP), high K(+) solution and by calcium chloride (CaCl2 ) in Ca(2+) -free and high K(+) , Ca(2+) -free solution. The EFS-evoked contractions were more sensitive to resveratrol and to NS1619-selective openers of big calcium-sensitive (BKCa ) channels, than NE-evoked contractions. Effects of resveratrol on the ATP-evoked contractions were weak. Blockers of BKCa channels partly inhibited the effect of resveratrol only in EFS-contracted preparations. Western blotting showed that RPV expressed KCa 1.1 protein. Inhibitors of ATP- and voltage-sensitive K(+) channels did not modify the effects of resveratrol. None of the antagonists of K(+) channels affected the resveratrol inhibition of NE-evoked contractions and effect of high concentrations of resveratrol on the EFS-evoked contractions. Resveratrol more potently inhibited CaCl2 than potassium chloride contractions of RPV. Thus, BKCa channels partly mediate the inhibitory effect of resveratrol on the neurogenic contractions of RPV. The smooth muscle Ca(2+) channels and/or Ca(2+) mobilizing through cells might be involved in the effects of resveratrol on the contractility of RPV. Our results are important for better understanding the impact of resveratrol on the portal circulation.
authors.affiliation: Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Dragana
authors.initials: D
authors.lastname: Protić
authors.forename: Bojana
authors.initials: B
authors.lastname: Beleslin-Čokić
authors.forename: Radmila
authors.initials: R
authors.lastname: Novaković
authors.forename: Vladimir
authors.initials: V
authors.lastname: Kanjuh
authors.forename: Helmut
authors.initials: H
authors.lastname: Heinle
authors.forename: Radisav
authors.initials: R
authors.lastname: Sćepanović
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Gojković-Bukarica
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002122:Calcium Chloride / Q000494:pharmacology; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D011169:Portal Vein / Q000187:drug effects* / Q000502:physiology; D011188:Potassium / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects*; D014920:Wine
chemical_list: D026902:Potassium Channel Blockers; D015221:Potassium Channels; D013267:Stilbenes; D000255:Adenosine Triphosphate; D002122:Calcium Chloride; D000077185:Resveratrol; D011188:Potassium; D009638:Norepinephrine
keywords: K+ channels; Western blotting; electrical field stimulation; rat portal vein; resveratrol