Developmental change in magnesium sulfate-induced relaxation of rabbit pulmonary arteries

Details

Serval ID
serval:BIB_0B08563DD626
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Developmental change in magnesium sulfate-induced relaxation of rabbit pulmonary arteries
Journal
Journal of Applied Physiology
Author(s)
Tolsa  J. F., Gao  Y., Raj  J. U.
ISSN
8750-7587 (Print)
Publication state
Published
Issued date
11/1999
Volume
87
Number
5
Pages
1589-94
Notes
In Vitro
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Nov
Abstract
Magnesium causes a variety of vascular smooth muscle to relax. The present study was designed to determine whether there is a developmental change in the magnesium-induced response of pulmonary vasculature. Isolated pulmonary arteries (PA) of newborn (1- to 3-day-old) and juvenile (4- to 6-wk-old) rabbits were suspended in organ chambers filled with modified Krebs-Ringer bicarbonate solution (95% O(2)-5% CO(2), 37.0 degrees C), and their isometric tension was recorded. In arteries preconstricted with endothelin-1 to a similar tension level, MgSO(4) caused greater relaxation of juvenile rabbit PA than that of the newborn rabbit PA. Verapamil, a voltage-dependent Ca(2+) channel blocker, attenuated magnesium-induced relaxation in juvenile rabbit PA but not in newborn PA. The uptake of Ca(2+) of juvenile rabbit PA was inhibited by MgSO(4), and the inhibition was attenuated by verapamil. The uptake of Ca(2+) of newborn rabbit PA was smaller than that of the juvenile PA and was not significantly affected by MgSO(4) and verapamil. These results demonstrate that there is a developmental increase in the dilator effect of MgSO(4) in rabbit PA. In newborn rabbit PA, an incomplete maturation of the voltage-dependent Ca(2+) channels may contribute to the smaller vasodilation induced by MgSO(4).
Keywords
Animals Animals, Newborn Calcium/metabolism Calcium Channel Blockers/pharmacology Calcium Channels/drug effects Female Magnesium Sulfate/*pharmacology Male Muscle Relaxation/drug effects Muscle, Smooth, Vascular/cytology/*drug effects Potassium Chloride/pharmacology Prostaglandins/pharmacology Pulmonary Artery/*drug effects Rabbits Verapamil/pharmacology
Pubmed
Web of science
Create date
28/01/2008 14:52
Last modification date
20/08/2019 13:32
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