Effect of aminophylline on coronary reactive and functional hyperaemic response in conscious dogs.
This study was undertaken to determine whether adenosine release from myocardial cells plays a role in coronary reactive and functional vasomotion. Reactive hyperaemic blood flow responses to 10 s complete occlusions and 400 ms diastolic occlusions of the left circumflex coronary artery and to the vasomotor responses to the increased cardiac demand following ventricular extra-activation were examined in a chronic, heart-blocked dog preparation during a control period and following intravenous bolus administration of aminophylline (5 mg X kg-1). Aminophylline administration resulted in a 19% decrease in the blood flow debt repayment ratio of 10 s reactive hyperaemic responses compared with the control period. However, administration of aminophylline had no effect on the coronary vascular response to 400 ms diastolic occlusions or to ventricular extra-activations. These observations indicate that adenosine may play a role in the coronary vascular response to prolonged interventions but that other factors, as yet unidentified, may be implicated in the beat-to-beat regulation of coronary vascular resistance.
D000628:Aminophylline / Q000494:pharmacology*; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects* / Q000503:physiopathology; D004195:Disease Models, Animal; D004285:Dogs; D006327:Heart Block / Q000503:physiopathology; D010100:Oxygen / Q000097:blood; D012039:Regional Blood Flow / Q000187:drug effects; D013806:Theophylline / Q000097:blood; D014655:Vascular Resistance / Q000187:drug effects*; D014666:Vasomotor System / Q000187:drug effects*
D000628:Aminophylline; D013806:Theophylline; D010100:Oxygen