Effect of hypoxia on endothelium-dependent relaxation of porcine coronary arteries and veins.
In isolated transverse strips of porcine coronary artery and rings of coronary vein both mild (pO2 = 70 +/- 2.6 mmHg) and severe (pO2 = 17.4 +/- 0.8 mmHg) hypoxia (30 min duration) produced a transient contraction depending on the severity of hypoxia. Hypoxia did not influence the contraction evoked by prostaglandin F2 alpha in coronary veins but inhibited it significantly in coronary arteries. In the venous preparations there was no change of the endothelium-dependent relaxation to bradykinin and acetylcholine during mild hypoxia but these responses were inhibited during exposure to severe hypoxia. The endothelium-dependent relaxation to bradykinin produced in coronary arteries was not modified by mild hypoxia but was inhibited in the higher concentration range of bradykinin by severe hypoxia. The results suggest a higher sensitivity of porcine coronary arteries to hypoxia compared to coronary veins that could be due to the different morphology (thickness) of the vessel wall. This may play a role in pathophysiology including hypoxic state during coronary vasospasm.
Vedernikov
Y P
YP
Department of Human Cardiovascular Pathology, All-Union Cardiology Research Centre, Academy of Medical Sciences, Moscow, USSR.
Gräser
T
T
Leisner
H
H
Tiedt
N
N
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000503:physiopathology; D001920:Bradykinin / Q000494:pharmacology; D003331:Coronary Vessels / Q000503:physiopathology*; D015237:Dinoprost / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D009126:Muscle Relaxation; D014661:Vasoconstriction; D014680:Veins / Q000503:physiopathology
D015237:Dinoprost; D000109:Acetylcholine; D001920:Bradykinin