[The relaxation of the coronary artery smooth muscles under the action of a high-potassium solution].
The relaxation of the smooth muscle circular strips of cattle coronary arteries was studied under the increasing [K+]O using a modified sucrose gap technique. The relaxation occurred in three cases: 1) when the elevated [K+]O was moderate (up to 40 mmol/l); 2) at the beginning of high [K+]O action (60-160 mmol/l); 3) when the [K+]O was elevated (up to 160 mmol/l) under the conditions of a calcium current blockade. In each case the relaxation was connected with slow depolarization of the smooth muscle cells membrane and depressed by beta-adrenergic blocking agent propranolol (10(-5) mol/l). The relaxant action of the high-potassium solution on the coronary smooth muscle is actualized via the noradrenaline release from intramural nerve endings.
Nikitina
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D000818:Animals; D002417:Cattle; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007552:Isotonic Solutions; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects* / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D011188:Potassium / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D012996:Solutions; D013806:Theophylline / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
D007552:Isotonic Solutions; C051865:Krebs-Ringer solution; D012996:Solutions; D011433:Propranolol; D013806:Theophylline; D014700:Verapamil; D011188:Potassium
Rasslablenie gladkikh myshts koronarnykh arteriĭ pri deĭstvii giperkalievogo rastvora.