Lack of production of thromboxane A2 by the sheep heart following coronary occlusion.
Blood pressure, heart rate and ECG were monitored continuously and coronary venous blood samples assayed for thromboxane B2. Arterio-coronary venous lactic acid differences were estimated. In anaesthetized sheep, 60 sec occlusions of the left circumflex coronary artery caused hypotension with little change in heart rate. Five minute occlusions produced similar changes accompanied by cardiac arrhythmias and a larger fall in blood pressure. In conscious sheep heart rate rose and blood pressure was maintained. ECG and lactic acid changes indicated severe myocardial ischaemia but not change in thromboxane release was detected. The apparent lack of involvement of thromboxane may reflect a relative inability of sheep platelets to produce this substance or a failure to provide an adequate stimulus for synthesis.
Carter
J
J
Reynoldson
J A
JA
Harper
C M
CM
Heywood
L H
LH
Thorburn
G D
GD
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure; D003327:Coronary Disease / Q000378:metabolism* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D009206:Myocardium / Q000378:metabolism*; D012756:Sheep; D013928:Thromboxane A2 / Q000096:biosynthesis* / Q000097:blood; D013997:Time Factors
D007773:Lactates; D019344:Lactic Acid; D013928:Thromboxane A2