Yazar "Dogan, N." seçeneğine göre listele

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    Effects of cooling and warming on 5-hydroxytryptamine- and acetylcholine-induced contractions of human umbilical vessels: role of nitric oxide
    (WILEY-BLACKWELL PUBLISHING, INC, 2008) Atalık, Kısmet Esra Nurullahoğlu; Kılıç, M.; Nurullahoğlu, Zahide Ülya; Dogan, N.
    The effects of cooling (to 28 degrees C) and warming (to 41 degrees C) on the vasoconstrictions induced by 5-hydroxytryptamine (5-HT) and acetylcholine (ACh) and the role of nitric oxide in these effects were analyzed in human umbilical artery and vein. 5-HT (10(-9)-10(-4) M) and ACh (10(-9)-10(-4) M) induced concentration-dependent contractions at 37, 28 and 41 degrees C. During cooling, the sensitivity, but not the maximal response, of 5-HT and ACh was significantly higher than at 37 degrees C; and during warming, again the sensitivity, but not the maximal response, of both contractile agents was significantly lower than at 37 degrees C. Neither cooling to 28 degrees C nor warming to 41 degrees C, after treatment with N(G)-nitro-L-arginine methyl esther (L-NAME, 10(-4) M), modify the effect of temperature in both vessels. These results suggest that cooling- and warming-induced responses in human umbilical artery and vein are independent of nitric oxide.
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    Effects of cooling on histamine-induced contractions of human umbilical artery: The role of ion channels
    (PROUS SCIENCE, SA, 2007) Atalik, K. E.; Kilic, M.; Nurullahqlu, Z. U.; Dogan, N.
    The effects of cooling (to 28 degrees C) on histamine (10(-9) - 3 x 10(-4) M)-induced contractions and the role of calcium (Ca2+), potassium (K-Ca(2+)) and sodium (Na+) channel blockers in the cooling-induced responses were investigated in the endothelium-denuded human umbilical artery. Concentration-response curves to histamine were isometrically recorded at 37 and 28 degrees C (control). The same procedure was repeated at 28 degrees C in the presence of tetraethylammonium (TEA, 10(-3) M), pilsicainide (10(-6) M), ouabain (10-6 M), caffeine (3 X 10-4 M), verapamil (10(-6) M) and also in Ca2+-free medium with ethylene glycol bis-(beta-aminoethyl ether) N,N,N-1,N-1-tetraacetic acid (EGTA). During cooling, the sensitivity, but not the maximal response, was significantly higher than 37 degrees C. Cooling to 28 degrees C after treatment with verapamil or pilsicainide decreased the sensitivity, whereas treatment with TEA and ouabain significantly increased sensitivity. Treatment with caffeine did not modify the effect of cooling. Furthermore, cooling to 28 degrees C after incubation in Ca(2+)free solution with EGTA decreased the sensitivity to histamine. The results of this study suggest the role of Ca2+, K-Ca(2+) and Na+-ion channels in the cooling-induced changes of human umbilical arteries treated with histamine. (C) 2007 Prous Science. All rights reserved.
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    EFFECTS OF OXIDATIVE STRESS ELICITED BY H2O2 DURING COOLING IN THE HUMAN UMBILICAL ARTERY
    (WILEY-BLACKWELL, 2011) Duman, I; Dogan, N.
    [Abstract not Available]
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    POSSIBLE MECHANISMS OF OXYDATIVE STRESS ELICITED BY HYDROGEN PEROXIDE IN THE HUMAN UMBILICAL ARTERY: AN IN VITRO STUDY
    (WILEY-BLACKWELL, 2011) Duman, I; Dogan, N.
    [Abstract not Available]
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    Role of the nitric oxide on diazoxide-induced relaxation of the calf cardiac vein and coronary artery during cooling
    (WILEY-BLACKWELL PUBLISHING, INC, 2009) Atalik, K. E.; Kilic, M.; Dogan, N.
    The effects of cooling (to 28 degrees C) on the vasodilation induced by diazoxide (10(-9)-3 x 10(-4) m) on carbachol-pre-contracted calf cardiac vein and coronary artery and the role of nitric oxide in these effects were analyzed. Diazoxide produced concentration-dependent relaxation of calf cardiac vein and coronary artery rings pre-contracted with carbachol (10(-6) m). During cooling, the pIC(50) values, but not the maximal responses, to diazoxide were significantly lower than at 37 degrees C in both preparations. Cooling to 28 degrees C in the presence of N(G)-nitro-L-arginine methyl ester (10(-4) m) did not modify the effect of temperature both in cardiac vein and coronary artery. These results suggest that cooling-induced changes of diazoxide in calf cardiac vein and coronary artery are independent of nitric oxide.