The role of K+ ions on the response to carbachol of calf coronary artery and cardiac vein during cooling.
The role of K+ ions on the vasoconstrictions induced by carbachol during cooling (28 degrees C) in the endothelium of a denuded calf coronary artery and cardiac vein (noncutaneous vessel) was studied. Carbachol (10(-9) - 3 x 10(-4) M) induced concentration-dependent contractions at both 37 degrees C and 28 degrees C. The sensitivity, but not the maximal response, of carbachol (10(-9) -3 x 10(-4) M) was significantly lower at 28 degrees C than at 37 degrees C. Cooling to 28 degrees C after treatment with tetraethylammonium (TEA, 10(-3) M) or ouabain (10(-5) M), after incubation in K+-free medium increased the sensitivity to carbachol in both preparations. The results suggest a role for K+ ions in the cooling-induced changes of noncutaneous vessels.
Atalik
K E
KE
Department of Pharmacology, Faculty of Medicine, University of Selçuk, Konya, Turkey. esraatalik@hotmail.com
Sahin
A S
AS
Ulusoy
H B
HB
Dogan
N
N
D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D002417:Cattle; D018679:Cholinergic Agonists / Q000494:pharmacology*; D003080:Cold Temperature; D003331:Coronary Vessels / Q000033:anatomy & histology / Q000187:drug effects; D004730:Endothelium, Vascular / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000502:physiology*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors; D019789:Tetraethylammonium / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects* / Q000502:physiology
D018679:Cholinergic Agonists; D004791:Enzyme Inhibitors; D026902:Potassium Channel Blockers; D010042:Ouabain; D019789:Tetraethylammonium; D002217:Carbachol; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium