[The effect of leukotriene LTC4 on the coronary vascular bed and on myocardial contractile function]

The effects of intracoronary LTC4 administration have been studied in narcotized dogs with an intact chest. LTC4 in doses of 0.5-40 micrograms produced a dose-dependent decrease in coronary flow, inhibition of myocardial contractility and disturbance of cardiac rhythm. A decrease in myocardial contractility was shown to take place before the signs of myocardial ischemia had appeared that could not be entirely due to the decrease in coronary blood flow. Ultrastructural changes in the endothelium of the coronary vessels have also been observed under the action of LTC4.