Response of rabbit ear artery to endothelin‐1 during cooling

• Published in: British journal of pharmacology 1991-11, Vol.104 (3), p.609-612
• Main Authors: Monge, L., García‐Villalón, A.L., Montoya, J.J., García, J.L., Gómez, B., Diéguez, G.
• Format: Article
• Language: English
• Subjects: Animals; Arginine - analogs & derivatives; Arginine - pharmacology; Arteries - drug effects; Biological and medical sciences; Blood vessels and receptors; Cold Temperature; cooling; Ear, External - blood supply; Endothelins - pharmacology; endothelin‐1; Endothelium; Endothelium, Vascular - drug effects; Fundamental and applied biological sciences. Psychology; In Vitro Techniques; Isometric Contraction - drug effects; Male; Meclofenamic Acid - pharmacology; Muscle, Smooth, Vascular - drug effects; NG-Nitroarginine Methyl Ester; NG‐nitro‐l‐arginine methyl ester (l‐NAME); nitric oxide; Nitric Oxide - pharmacology; Nitroprusside - pharmacology; Potassium Chloride - pharmacology; rabbit ear artery; Rabbits; Regional Blood Flow - drug effects; skin arteries; temperature; Vertebrates: cardiovascular system
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1111/j.1476-5381.1991.tb12477.x

1 The effects of cooling on the response of rabbit central ear artery to endothelin‐1 and the role of the endothelium in these effects were studied in 2 mm long cylindrical arterial segments. 2 Concentration‐response curves for endothelin‐1 (10−10–3 × 10−7 m) were recorded isometrically in arteries with and without endothelium at 37°C and during cooling (24°C). To analyze further the endothelial mechanisms of the response to endothelin‐1 during cooling, the effects of this peptide in the presence of NG‐nitro‐l‐arginine methyl ester (l‐NAME) (10−4 m) or meclofenamate (10−5 m) were also determined. 3 In every condition tested, endothelin‐1 produced a marked, concentration‐dependent arterial contraction. Sensitivity of intact arteries to this peptide was consistently lower at 24°C than at 37°C. At 37°C there were comparable responses of arteries with and without endothelium, but at 24°C arteries without endothelium showed a higher sensitivity than intact arteries to endothelin‐1. 4 l‐NAME (10−4 m) increased the maximal contraction at 37°C, and both the sensitivity and maximal contraction at 24°C of intact arteries to endothelin‐1. Meclofenamate (10−5 m) did not affect the arterial response to endothelin‐1. 5 Sensitivity of arteries with and without endothelium to nitroprusside (10−9–10−3 m) was significantly decreased during cooling, and endothelium removal did not affect the relaxation to this nitrovasodilator. 6 These results suggest that cooling decreases sensitivity of cutaneous arteries (ear artery) to endothelin‐1 probably by increasing the availability of endothelial nitric oxide.