Effect of cold cardioplegic solution and hypothermia on response to acetylcholine in perfused epicardial coronary artery of pig.
The effect of cold cardioplegic solution and hypothermia on the response to acetylcholine, a major postganglionic neurotransmitter of the parasympathetic nervous system, was studied using perfused epicardial coronary arteries of pigs. Cold crystalloid cardioplegic solution (5 degrees C) and hypothermia including topical cooling with slushed ice significantly augmented the coronary flow reduction by acetylcholine at one and two hours after rewarming. Cold Krebs-Henseleit solution (5 degrees C) with hypothermia showed similar effects. However, cardioplegic solution at 37 degrees C did not affect the responsiveness. The coronary flow reduction induced by potassium chloride (60 mmol/L) did not change even after the administration of cold cardioplegic solution (5 degrees C) or cold Krebs-Henseleit solution (5 degrees C), indicating that cooling did not necessarily augment the coronary contractile response generally. It is concluded that cooling and subsequent rewarming can potentiate the contractile response of the coronary artery of the pig to acetylcholine. This suggests that cold cardioplegic solution with hypothermia can promote intraoperative coronary spasm upon activation of the parasympathetic nervous system.
Furusho
N
N
Department of Pharmacology, Kumamoto University School of Medicine, Japan.
Araki
H
H
Nishi
K
K
Miyauchi
Y
Y
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000502:physiology; D001783:Blood Flow Velocity / Q000187:drug effects; D002314:Cardioplegic Solutions / Q000494:pharmacology; D003080:Cold Temperature; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D007036:Hypothermia, Induced; D066298:In Vitro Techniques; D010496:Pericardium; D011188:Potassium / Q000494:pharmacology; D017680:Potassium Compounds; D013552:Swine
D002314:Cardioplegic Solutions; D017680:Potassium Compounds; C018369:potassium cardioplegic solution; D000109:Acetylcholine; D011188:Potassium