PREGNANCY-INDUCED ALTERATIONS OF RELAXATION IN RESPONSE TO MAGNESIUM IN THE RAT AORTA MAY BE DUE TO PLASMA-BORNE AGENTS

Citation
M. Ezimokhai et al., PREGNANCY-INDUCED ALTERATIONS OF RELAXATION IN RESPONSE TO MAGNESIUM IN THE RAT AORTA MAY BE DUE TO PLASMA-BORNE AGENTS, Heart and vessels, 10(4), 1995, pp. 197-203
Citations number
NO
Categorie Soggetti
Cardiac & Cardiovascular System","Peripheal Vascular Diseas
Journal title
ISSN journal
09108327
Volume
10
Issue
4
Year of publication
1995
Pages
197 - 203
Database
ISI
SICI code
0910-8327(1995)10:4<197:PAORIR>2.0.ZU;2-E
Abstract
The influence of plasma from pregnant and nonpregnant humans was exami ned, using magnesium-induced relaxation of precontracted rat aortic ri ngs. The results showing magnesium-induced relaxation of aortic rings from pregnant and nonpregnant rats were compared. In rat aortic rings incubated in plasma from pregnant patients, magnesium was more potent in relaxing the precontractions induced by potassium chloride than in relaxing-those induced by phenylephrine. The magnesium-induced relaxat ion of rings incubated in plasma from normal pregnant subjects was sim ilar to that in unincubated rings from normal pregnant rats. Neither t he removal of endothelium nor pretreatment with indomethacin affected the pattern of responses in the rings. The results suggest that the ef fects of pregnancy on magnesium-induced relaxation of the rat aorta ma y be mediated by plasma-borne agents, and the mechanisms by which the agents alter the relaxation do not involve either the vascular endothe lium or prostaglandin synthesis.