The influence of oxygen tension on membrane potential and tone of canine carotid artery smooth muscle.
In vascular smooth muscle of canine carotid artery segments the decrease in oxygen tension from approximately 550 mmHg to approximately 30 mmHg leads to a dose-dependent hyperpolarization and relaxation of the vessel strip. At PO2 values below approximately 15-20 mmHg depolarization and subsequent contraction were found. All changes of the parameters investigated were reversible. Indomethacin (10(-5) M) had no significant effect on the hypoxia-dependent potential and tension changes. The hyperpolarized part of the activation curve was obtained by plotting tension versus membrane potential values.
Grote
J
J
Institute of Physiology I, University of Bonn, Germany.
Siegel
G
G
Zimmer
K
K
Adler
A
A
D000818:Animals; D002339:Carotid Arteries / Q000187:drug effects / Q000502:physiology*; D004285:Dogs; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008564:Membrane Potentials; D009129:Muscle Tonus; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure
D010100:Oxygen; D007213:Indomethacin