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Modulation by endothelin‐1 of the coronary vasoconstriction after ischemia‐reperfusion
Author(s) -
GarciaVillalon Angel Luis,
Amezquita Yesika Maria,
Monge Luis,
Fernandez Nuria,
Salcedo Adely,
Dieguez Godofredo
Publication year - 2007
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.21.6.a1382
Subject(s) - vasoconstriction , thromboxane a2 , contraction (grammar) , ischemia , endothelin receptor , phenylephrine , medicine , endothelins , endothelin 1 , thromboxane , endocrinology , hypoxic pulmonary vasoconstriction , agonist , cardiology , anesthesia , receptor , platelet , blood pressure
Endothelin‐1 at subthreshold concentrations may increase the response to other vasoconstrictors. To analyze whether this effect of endothelin‐1 is affected by ischemia‐reperfusion, isolated hearts of rats were perfused in a Langendorff preparation and subjected to 30 min total ischemia followed by 15 min of reperfusion. Then coronary artery segments 2 mm long were dissected and prepared for isometric tension recording in organ baths. U46619 (10 −7 M) produced contraction which was not significantly different after ischemia‐reperfusion (92±17 mg, 5 animals) or time‐control perfusion (147±28 mg, 7 animals, P>0.05). After pre‐treatment during 15 min with endothelin‐1 (3×10 −10 M), the contraction to U46619 increased in time‐controls (74±22 %) but not after ischemia‐reperfusion (P<0.05; 6 animals). The specific α1‐adrenergic agonist phenylephrine produced small contraction (15±3 mg) which was not potentiated by endothelin‐1 (10 −9 M). This suggests that endothelin‐1 may potentiate the coronary vasoconstriction to activation of thromboxane A 2 receptors but not of adrenoceptors. This potentiating effect of endothelin‐1 on activation of thromboxane A 2 receptors is reduced after ischemia reperfusion. (This work was supported, in part, by BFU2004‐04054)