The interactions of platelet-derived mediators on isolated canine coronary arteries.
The interactions of 5-hydroxytryptamine (5-HT) and a thromboxane A2 mimetic, U44069, were investigated on rings of canine coronary arteries. 5-HT (10(-8) - 10(-5) M) and U44069 (10(-9) - 10(-6) M) produce coronary vasoconstriction which is potentiated by indomethacin (3 X 10(-6) M). In the presence of 10(-9) M 5-HT, U44069-induced vasoconstriction is enhanced. Similarly, 10(-9) M U44069 enhances the effects of 5-HT. In both cases this potentiation is greatest in the presence of indomethacin. Synergism between the platelet-derived mediators could contribute to coronary vasospasm and myocardial ischaemia.
D000818:Animals; D001792:Blood Platelets / Q000502:physiology; D003331:Coronary Vessels / Q000187:drug effects*; D004285:Dogs; D005260:Female; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D010656:Phenylephrine / Q000494:pharmacology; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology*; D012701:Serotonin / Q000494:pharmacology*
D011450:Prostaglandin Endoperoxides, Synthetic; D010656:Phenylephrine; D012701:Serotonin; C028429:U 44069; D007213:Indomethacin