Role of the nitric oxide on diazoxide-induced relaxation of the calf cardiac vein and coronary artery during cooling.
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.
Atalik
K E
KE
Faculty of Meram Medicine, Department of Pharmacology, University of Selçuk, Konya 42080, Turkey. esraatalik@hotmail.com
Kiliç
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M
Doğan
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N
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002417:Cattle; D003080:Cold Temperature; D003331:Coronary Vessels / Q000187:drug effects / Q000378:metabolism; D003981:Diazoxide / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*
D014665:Vasodilator Agents; D009569:Nitric Oxide; D002217:Carbachol; D003981:Diazoxide; D019331:NG-Nitroarginine Methyl Ester