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On the Mechanism of Action of the Relaxing Effect of the 5,4´‐Dihidroxi‐6,7,8,3´‐Tetrametoxi‐Flavone, Flavone A, on Vascular Smooth Muscle of the Rat
Author(s) -
Algara Suárez Paola,
Navarro Huerta M Patricia,
ValleAguilera J Roberto,
BritoOrta M Dolores,
RodriguezMenchaca Aldo,
ArechigaFigueroa Ivan,
EspinosaTanguma Ricardo,
GonzalezChavez Marco
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.773.8
Subject(s) - flavones , chemistry , vascular smooth muscle , mechanism (biology) , action (physics) , pharmacology , smooth muscle , medicine , physics , chromatography , quantum mechanics
We purified a vasorelaxant compound: 5,4´‐DIHIDROXI‐6,7,8,3´‐TETRAMETOXI‐FLAVONE (FA), from an extract of Larrea tridentata, an endemic plant from the mexican highlands and explored the mechanisms undrlying such vasorelaxation. Methods: Mesenteric artery rings were isolated from male guinea pigs for isometric force measurements and ionic current measument for Ca 2+ and K + infreshly isolated smooth muscle cells. Results: 10 μM FA completely relaxed vascular rings contracted with phenylephrine in a dose‐dependent fashion with an EC 50 = 3 μM and 5 μM for endothelium intact and endothelium‐free tissue, respectively. The relaxant effect of FA was not affected by maximal doses of nifedipine, verapamil or iberiotoxin. Nevertheless, the relaxant effect was partialy abolished by addition of 10m M Tetraethylammonium (TEA). In accordance to this, Ca 2+ currents evoked by depolarization were not affected by FA, whereas TEA‐sensitive K + currents, were increased upon addition of FA. Conclusions vasorelaxation due to FA is partly due to activation of Kv currents in an endothelium independent fashion. Supported by: C14‐FAI‐04‐34.34, UASLP