Atalik, KESahin, ASDogan, N2020-03-262020-03-2620050379-03552013-0155https://dx.doi.org/10.1358/mf.2005.27.9.939342https://hdl.handle.net/20.500.12395/19968The effects of wartning (to 41 degrees C) oil the serotonin (5-HT, 10(-8)-3 x 10(-3) M)- and carbachol (10(-9)-3 x 10(-4) M)-induced contractions and the role of calcium (Ca2+). potassium (K+), and sodium (Na+) channel blockers, in the warming-induced responses were investigated in the calf cardiac vein. Concentration-response curves to 5-HT and carbachol were isometrically recorded at 37 and 41 degrees C (control). The same procedure was repeated at 41 degrees C in the presence of verapamil (10(-6) M), caffeine (3 x 10(-4) M), tetraethylammonium (TEA, 10(-3) M), flecainide (10(-6) M), and also in the Ca2+-free medium with ethlylene glycol bis(beta-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA). During warning, the sensitivity, but not the maximum response, was significantly higher. Warming to 41 degrees C after treatment with verapamil or flecainide decreased the sensitivity, whereas treatment with caffine increased the sensitivity significantly. Treatment with TEA (lid not modify the effect of warming. Furthermore, warming to 41 degrees C after incubation in Ca2+-free solutions with EGTA decreased the sensitivity to 5-HT and carbachol. The results of this study suggest the role for Ca2+ and Na+ ions in the warming-induced changes of cardiac vein treated with 5-HT and carbachol. (c) 2005 Prous Science. All right reserved.en10.1358/mf.2005.27.9.939342info:eu-repo/semantics/openAccessCa2+K-Ca(2+)and Na+ ion channel blockerscardiac veinwarmingArticle27965365716357951N/AWOS:000234147400007Q4