In vitro pharmacologic effect of two endothelin-1 antagonists on equine colonic arteries and veins.

摘要: OBJECTIVE To evaluate the effectiveness of 2 potential endothelin (ET)-1 antagonists in blocking contractile responses equine colonic vessels to increasing concentrations ET-1. SAMPLE POPULATION Mesenteric from 6 clinically healthy horses. PROCEDURE Colonic (arterial and venous rings) were placed organ baths with oxygenated Tyrode solution at 37 C. Each was attached a force transducer interfaced polygraph, g tension applied equilibrated for 45 minutes. Then, B-1 (PD 142893) B-2 145065) ET-1 tested. One ring each vessel type used as control determining concentration-response relationships (10(-10) 10(-6)M). Three rings incubated 3 antagonist (10(-7), 10(-6), 10(-5) M) 30 minutes before ET induced contractions determined. The maximum response pA2 values RESULTS Vessels contracted concentration-dependent manner Arteries responded slowly but reached greater contractions. Veins immediately sustained Both inhibited significant differences 10(-6) 10(-5)M arteries M veins. Complete blockade observed (10(-5)M). 8.26 6.82 veins, respectively, whereas they 8.25 7.21 B-2. CONCLUSION AND CLINICAL RELEVANCE effectively blocked ET-1-induced vessels. Because is water soluble caused complete M, it appears be preferred antagonist.