title: Synchronization in the Heart Rate and the Vasomotion in Rat Aorta: Effect of Arsenic Trioxide.
abstract: Arsenic trioxide (As2O3) is used clinically in the management of acute promyelocytic leukemia, and the use of electrocardiogram (ECG) in this management is important as arsenic use may cause distortion of the electrical properties with its attendant sequel. We studied the effect of As2O3 on vasomotion in rat aortic rings using isometric tension recordings and ECG in anesthetized rats. The results showed that As2O3 (10(-5) M) significantly (p < 0.01) reduced the frequency of acetylcholine (10(-5) M ACh)- and KCl (10 mM)-induced vasomotion, and it also increased the relaxation time (R t) of vasomotion. This effect was restored by 10(-8) M sodium nitroprusside (nitric oxide donor). ACh-induced NO release in the aorta was blunted in the presence of As2O3. The corrected QT interval (QTc) of the ECG, and time dilation (T d) of the pulse wave in the tail artery of the anesthetized rat were significantly (p < 0.05) increased in the arsenic-treated group (50 ppb As) versus control. In conclusion, data suggest that arsenic-induced reduction in vasomotion frequency of the isolated aortic rings is associated with a decreased bioavailability of NO, an increase in QTc and a decrease in the frequency of the pulse wave generated by the cardiac cycle in anesthetized rats.
authors: Experimental Physiology Laboratory (EPhyL), Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile.
authors: Fredi
authors: F
authors: Cifuentes
authors: Departamento de Ciencias Químicas y Farmacéuticas, Facultad de Ciencias de la Salud, Universidad Arturo Prat, 1110939, Iquique, Chile. palacios.unap@gmail.com.
authors: Javier
authors: J
authors: Palacios
authors: Department of Basic Medical Sciences Physiology Section, Faculty of Medical Sciences, The University of the West Indies, Mona, Kingston 7, Jamaica, W.I.
authors: Chukwuemeka R
authors: CR
authors: Nwokocha
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity*; D001011:Aorta / Q000187:drug effects*; D000077237:Arsenic Trioxide; D001152:Arsenicals; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D066298:In Vitro Techniques; D007537:Isometric Contraction; D008133:Long QT Syndrome / Q000139:chemically induced / Q000503:physiopathology; D008297:Male; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010087:Oxides / Q000633:toxicity*; D015221:Potassium Channels / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D001152:Arsenicals; D020030:Nitric Oxide Donors; D010087:Oxides; D015221:Potassium Channels; D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine; D000077237:Arsenic Trioxide
keywords: Aorta rat; Arsenic; Electrocardiogram; K+ channels; Nitric oxide; Pulse wave; Vasomotion