Balance between endothelium-mediated dilating and direct constricting actions of serotonin on resistance vessels in the isolated rabbit heart.
To determine whether endothelium-derived relaxing factor (EDRF) contributes to the vasomotor action of serotonin (5-HT) in the coronary resistance bed, we used haemoglobin as an inhibitor of EDRF in isolated perfused rabbit hearts. The 5-HT-induced dilatation (14 +/- 2% change in vascular resistance) was converted to constriction (10 +/- 3% change) in the presence of haemoglobin, while the vasodilator responses to papaverine were not attenuated. This is consistent with a role for EDRF in the mediation of 5-HT-induced coronary resistance vessel dilatation.
Institute of Applied Physiology, University of Freiburg, F.R.G.
D J
DJ
Stewart
J
J
Holtz
U
U
Pohl
E
E
Bassenge
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects*; D004730:Endothelium, Vascular / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D006454:Hemoglobins / Q000502:physiology; D066298:In Vitro Techniques; D007213:Indomethacin / Q000031:analogs & derivatives / Q000494:pharmacology; D011817:Rabbits; D012701:Serotonin / Q000502:physiology*; D014655:Vascular Resistance / Q000187:drug effects
D006454:Hemoglobins; D012701:Serotonin; D007213:Indomethacin