Oxygen-induced contraction in the guinea pig neonatal ductus arteriosus
Details
Serval ID
serval:BIB_424C86CE7DAB
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Oxygen-induced contraction in the guinea pig neonatal ductus arteriosus
Journal
Circulation Research
ISSN
0009-7330 (Print)
Publication state
Published
Issued date
10/1981
Volume
49
Number
4
Pages
997-1002
Notes
Journal Article
Research Support, U.S. Gov't, P.H.S. --- Old month value: Oct
Research Support, U.S. Gov't, P.H.S. --- Old month value: Oct
Abstract
We investigated the mechanism of oxygen-induced contractions in ductus arteriosus isolated from neonatal guinea pig. A preparation equilibrated at low Po2 (less than 40 mm Hg) displayed a steady membrane potential of -54.8 mV. Application of oxygen (Po2 (less than approximately or equal to 300 mm Hg) resulted in: (1) stepwise development of tension coupled to action potentials and (2) sustained membrane depolarization to -32.9 mV associated with tonic contraction. Mechanical sensitivity to oxygen persisted at any[K]o up to 126 mM, and tension was always larger at a given [K]o or a given membrane potential with high Po2 than with low Po2. The change in membrane potential per decade change in [K]o was 35 mV at low Po2 and 16 mV at high Po2. Oxygen contractions occurred when the ductal strips were bathed in K-free media or exposed to ouabain. We conclude that oxygen caused a conductance change in the sarcolemma resulting in depolarization, which is coupled to contraction. There is also evidence of a membrane potential-independent contraction mechanism.
Keywords
Animals
Ductus Arteriosus/*physiology
Female
Guinea Pigs
Membrane Potentials
Myocardial Contraction/*drug effects
Neuromuscular Depolarizing Agents/pharmacology
Ouabain/pharmacology
Oxygen/*pharmacology
Potassium/pharmacology
Potassium Deficiency
Pregnancy
Stress, Mechanical
Pubmed
Web of science
Create date
24/01/2008 20:33
Last modification date
20/08/2019 13:44