Related Experiment Videos
Unique coronary vasodilator induction by leukotriene D4.
The American Journal of Physiology
|September 1, 1985
Summary
Leukotriene D4 initially constricts coronary blood flow but then induces a unique vasodilator factor. This factor, produced by platelets, explains the escape from constriction during sustained infusion.
Area of Science:
- Cardiovascular Physiology
- Pharmacology
- Biochemistry
Background:
- Leukotriene D4 (LTD4) causes significant reductions in coronary blood flow (CBF) and myocardial contractility.
- A phenomenon of 'escape' is observed, where CBF and contractility return towards baseline despite continued LTD4 administration.
Purpose of the Study:
- To elucidate the mechanism behind the escape from LTD4-induced coronary vasoconstriction.
- To identify the nature of the factor responsible for the observed vasodilation.
Main Methods:
- Intracoronary infusion of LTD4 and subsequent reinfusion of coronary venous plasma.
- Comparison of LTD4-induced effects with vasopressin or mechanical occlusion.
- In vitro incubation of whole blood, platelet-rich plasma, and platelet-poor plasma with LTD4.
Main Results:
- Plasma from LTD4-infused coronary veins induced coronary vasodilation upon reinfusion.
- LTD4-induced vasodilation was replicated by infusing plasma from LTD4-incubated whole blood or platelet-rich plasma, but not platelet-poor plasma.
- The induced vasodilator factor was stable and distinct from known vasoactive substances.
Conclusions:
- LTD4 induces the production of a unique coronary vasodilator factor.
- Platelets are essential for the production of this LTD4-induced vasodilator factor.
- This factor likely mediates the escape from LTD4-induced coronary vasoconstriction.