Author + information
- Received March 26, 1985
- Revision received June 11, 1985
- Accepted June 20, 1985
- Published online November 1, 1985.
- Thomas Wargovich, MD,
- Jawahar Mehta, MD, FACCa,
- Wilmer W. Nichols, PhD, FACC,
- Carl. J. Pepine, MD, FACC and
- C. Richard Conti, MD, FACC
- ↵aAddress for reprints: Jawahar L. Mehta, MD, Department of Medicines University of Florida, Box J-277. J. Hillis Miller Health Center, Gainesville, Florida 32610.
The hemodynamic effects of intracoronary leukotriene C4(0.3 to 10.0 µg) in seven anesthetized dogs with normal and severely narrowed coronary arteries were examined. Intracoronary leukotriene C4caused a significant dose-related reduction in coronary blood flow in both normal and narrowed coronary arteries with no effect on heart rate or mean arterial pressure. However, left ventricular end-diastolic pressure increased at the 10.0 µg dose. The reduction of blood flow in normal and narrowed coronary arteries in response to leukotriene C4was similar. At the peak effects of leukotriene C4, there was evidence of intracoronary thromboxane A2release. To examine the contribution of thromboxane A2release to the coronary vasoconstrictor effects of leu-kotriene C4dogs were administered leukotriene C4after indomethacin pretreatment. The decrease in coronary blood flow was not significantly affected by pretreatment of the animals with indomethacin. However, indomethacin lowered baseline levels of thromboxane B2and blocked the release of thromboxane A2after leukotriene C4administration.
Thus, intracoronary leukotriene C4causes direct dosedependent decrease in coronary blood flow of similar magnitude in both normal and narrowed coronary arteries. These coronary hemodynamic effects of leukotriene C4in dogs are not mediated by release of thromboxane A2. Leukotriene C4released from activated leukocyte in the intracoronary thrombus or in the injured myocardium may reduce coronary blood flow and adversely influence the fate of the affected myocardial tissue.
This study was supported by a grant-in-aid from the American Heart Association, Florida Affiliates St. Petersburg, Florida and presented in part at the 34th Annual Scientific Session of the American College of Cardiology. Anaheim, California, March 10 to 14, 1985.
- Received March 26, 1985.
- Revision received June 11, 1985.
- Accepted June 20, 1985.
- American College of Cardiology Foundation