|   | 
Details
   web
Record
Author (up) Williams, D.O.; Boatwright, R.B.; Rugh, K.S.; Garner, H.E.; Griggs, D.M.J.
Title Myocardial blood flow, metabolism, and function with repeated brief coronary occlusions in conscious ponies Type Journal Article
Year 1991 Publication The American journal of physiology Abbreviated Journal Am J Physiol
Volume 260 Issue 1 Pt 2 Pages H100-9
Keywords Animals; Consciousness/*physiology; Coronary Circulation/*physiology; Coronary Disease/pathology/*physiopathology; Disease Models, Animal; Hemodynamic Processes/physiology; Horses/*physiology; Hydrogen/metabolism; Lactates/metabolism; Myocardium/*metabolism/pathology; Norepinephrine/metabolism; Potassium/metabolism; Regional Blood Flow
Abstract Studies were performed in the conscious pony instrumented with a Doppler flow probe and hydraulic occluder on the left anterior descending coronary artery (LAD), sonomicrometry crystals and intraventricular micromanometer in the left ventricle, and catheters in the left atrium and anterior interventricular vein. Two-minute LAD occlusions were performed every 30 min continuously or during working hours. Data on release of catabolites (potassium, hydrogen ions, and lactate) and norepinephrine from the initially dysfunctional region were obtained periodically during a regimen of 445 +/- 56 occlusions in six animals. Regional myocardial blood flow was measured (microsphere method) before and after an occlusion regimen in four animals. Marked release of catabolites and norepinephrine from the initially dysfunctional region was noted in association with early occlusions when myocardial segment function was severely reduced. With further occlusions, release of these substances decreased while segment function improved. Blood flow was markedly decreased in the initially dysfunctional region during an early occlusion but was at the control level during a later occlusion. Although the metabolic findings are consistent with protection due to “ischemic preconditioning” and no increase in collateral perfusion, the inverse relationship noted between catabolite release and segment function is best explained by flow-dependent mechanisms. These results, together with the myocardial blood flow data, serve to validate a previous assumption that protection against regional myocardial dysfunction under these conditions is due to increased collateral perfusion.
Address Department of Physiology, University of Missouri, Columbia 65212
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-9513 ISBN Medium
Area Expedition Conference
Notes PMID:1992786 Approved no
Call Number refbase @ user @ Serial 98
Permanent link to this record