Effects of alinidine on exercise-induced regional contractile dysfunction in dogs.
The effects of the bradycardiac agent alinidine on hemodynamic parameters and regional contractile function were investigated in 6 chronically instrumented dogs trained to submit to 5 consecutive treadmill exercise runs. The experiments were performed during stenosis of the circumflex branch of the left coronary artery (LCX). After 2 control runs which had induced regional contractile dysfunction of comparable intensity, alinidine was infused intravenously at a dosage of 1 mg/kg per 5 min. The drug significantly reduced the resting function of both the LCX area (-16%) and the area perfused by the unstenosed anterior descending branch of the left coronary artery (LAD, -3%). However, the exercise-induced dysfunction of the LCX area was markedly improved in the 1st post-drug run and completely abolished during the 2nd and 3rd post-drug runs. As indicated by the reduction of heart rate (-18%) and positive dp/dtmax (-24%) during peak exercise, this improvement may be attributed to a bradycardiac and a negative inotropic effect of this drug. Further benefit may be ascribed to a decreased in arterial blood pressure after alinidine.
D000818:Animals; D002317:Cardiovascular Agents / Q000494:pharmacology*; D003000:Clonidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D005082:Physical Exertion; D013997:Time Factors
D002317:Cardiovascular Agents; C022192:alinidine; D003000:Clonidine