Magnesium sulfate and diphenylhydantoin relax canine middle cerebral artery contracted with the thromboxane-a2 analogue u46619 by different mechanisms

Implications for the management of eclampsia

Michael A. Belfort, George Saade, Kenneth J. Moise, Brian Kirshon, Paul M. Vanhoutte

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Objectives: To investigate the relaxant effect of MgSO4 and diphenylhydantoin on isolated canine middle cerebral artery (MCA) rings contracted with the thromboxane-A2 analogue U46619. Methods: Canine MCA rings, with and without endothelium, were suspended in organ chambers for isometric tension recording. They were contracted with U46619 in the presence of indomethacin, with and without nitro-l-arginine (NLA). Cumulative dose-response curves were performed using MgSQ4 (10-8 M to 10-2 M) and diphenylhydantoin (10-9 M to 10-3 M). Main Outcome Measures: Tension at each concentration of the study drug expressed as a percentage of the maximum tension developed with U46619; area under the concentration response curve. Results: Both MgSO4 and diphenylhydantoin relaxed the MCA rings irrespective of the presence of endothelium. Diphenylhydantoin caused an endothelium-dependent relaxation at concentrations above 3 10-5 M, unaffected by NLA. Conclusions: MgSO4 relaxes canine MCA by a direct smooth muscle effect independent of the endothelium. Diphenylhydantoin causes an endothelium-dependent relaxation of canine MCA at concentrations above 3 10-5 M, unrelated to nitric oxide. MgSO4 and diphenylhydantoin may both help to prevent seizures in patients with eclampsia by reducing me potential for cerebral vasospasm.

Original languageEnglish (US)
Pages (from-to)51-60
Number of pages10
JournalHypertension in Pregnancy
Volume13
Issue number1
DOIs
StatePublished - 1994
Externally publishedYes

Fingerprint

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid
Magnesium Sulfate
Eclampsia
Thromboxane A2
Middle Cerebral Artery
Phenytoin
Canidae
Endothelium
Arginine
Intracranial Vasospasm
Indomethacin
Smooth Muscle
Nitric Oxide
Seizures
Outcome Assessment (Health Care)
Pharmaceutical Preparations

Keywords

  • Cerebral vasospasm
  • Diphenylhydantoin
  • Magnesium sulfate

ASJC Scopus subject areas

  • Obstetrics and Gynecology
  • Internal Medicine

Cite this

Magnesium sulfate and diphenylhydantoin relax canine middle cerebral artery contracted with the thromboxane-a2 analogue u46619 by different mechanisms : Implications for the management of eclampsia. / Belfort, Michael A.; Saade, George; Moise, Kenneth J.; Kirshon, Brian; Vanhoutte, Paul M.

In: Hypertension in Pregnancy, Vol. 13, No. 1, 1994, p. 51-60.

Research output: Contribution to journalArticle

@article{7016d2c58b5140d0a72e967628b05153,
title = "Magnesium sulfate and diphenylhydantoin relax canine middle cerebral artery contracted with the thromboxane-a2 analogue u46619 by different mechanisms: Implications for the management of eclampsia",
abstract = "Objectives: To investigate the relaxant effect of MgSO4 and diphenylhydantoin on isolated canine middle cerebral artery (MCA) rings contracted with the thromboxane-A2 analogue U46619. Methods: Canine MCA rings, with and without endothelium, were suspended in organ chambers for isometric tension recording. They were contracted with U46619 in the presence of indomethacin, with and without nitro-l-arginine (NLA). Cumulative dose-response curves were performed using MgSQ4 (10-8 M to 10-2 M) and diphenylhydantoin (10-9 M to 10-3 M). Main Outcome Measures: Tension at each concentration of the study drug expressed as a percentage of the maximum tension developed with U46619; area under the concentration response curve. Results: Both MgSO4 and diphenylhydantoin relaxed the MCA rings irrespective of the presence of endothelium. Diphenylhydantoin caused an endothelium-dependent relaxation at concentrations above 3 10-5 M, unaffected by NLA. Conclusions: MgSO4 relaxes canine MCA by a direct smooth muscle effect independent of the endothelium. Diphenylhydantoin causes an endothelium-dependent relaxation of canine MCA at concentrations above 3 10-5 M, unrelated to nitric oxide. MgSO4 and diphenylhydantoin may both help to prevent seizures in patients with eclampsia by reducing me potential for cerebral vasospasm.",
keywords = "Cerebral vasospasm, Diphenylhydantoin, Magnesium sulfate",
author = "Belfort, {Michael A.} and George Saade and Moise, {Kenneth J.} and Brian Kirshon and Vanhoutte, {Paul M.}",
year = "1994",
doi = "10.3109/10641959409084171",
language = "English (US)",
volume = "13",
pages = "51--60",
journal = "Hypertension in Pregnancy",
issn = "1064-1955",
publisher = "Informa Healthcare",
number = "1",

}

TY - JOUR

T1 - Magnesium sulfate and diphenylhydantoin relax canine middle cerebral artery contracted with the thromboxane-a2 analogue u46619 by different mechanisms

T2 - Implications for the management of eclampsia

AU - Belfort, Michael A.

AU - Saade, George

AU - Moise, Kenneth J.

AU - Kirshon, Brian

AU - Vanhoutte, Paul M.

PY - 1994

Y1 - 1994

N2 - Objectives: To investigate the relaxant effect of MgSO4 and diphenylhydantoin on isolated canine middle cerebral artery (MCA) rings contracted with the thromboxane-A2 analogue U46619. Methods: Canine MCA rings, with and without endothelium, were suspended in organ chambers for isometric tension recording. They were contracted with U46619 in the presence of indomethacin, with and without nitro-l-arginine (NLA). Cumulative dose-response curves were performed using MgSQ4 (10-8 M to 10-2 M) and diphenylhydantoin (10-9 M to 10-3 M). Main Outcome Measures: Tension at each concentration of the study drug expressed as a percentage of the maximum tension developed with U46619; area under the concentration response curve. Results: Both MgSO4 and diphenylhydantoin relaxed the MCA rings irrespective of the presence of endothelium. Diphenylhydantoin caused an endothelium-dependent relaxation at concentrations above 3 10-5 M, unaffected by NLA. Conclusions: MgSO4 relaxes canine MCA by a direct smooth muscle effect independent of the endothelium. Diphenylhydantoin causes an endothelium-dependent relaxation of canine MCA at concentrations above 3 10-5 M, unrelated to nitric oxide. MgSO4 and diphenylhydantoin may both help to prevent seizures in patients with eclampsia by reducing me potential for cerebral vasospasm.

AB - Objectives: To investigate the relaxant effect of MgSO4 and diphenylhydantoin on isolated canine middle cerebral artery (MCA) rings contracted with the thromboxane-A2 analogue U46619. Methods: Canine MCA rings, with and without endothelium, were suspended in organ chambers for isometric tension recording. They were contracted with U46619 in the presence of indomethacin, with and without nitro-l-arginine (NLA). Cumulative dose-response curves were performed using MgSQ4 (10-8 M to 10-2 M) and diphenylhydantoin (10-9 M to 10-3 M). Main Outcome Measures: Tension at each concentration of the study drug expressed as a percentage of the maximum tension developed with U46619; area under the concentration response curve. Results: Both MgSO4 and diphenylhydantoin relaxed the MCA rings irrespective of the presence of endothelium. Diphenylhydantoin caused an endothelium-dependent relaxation at concentrations above 3 10-5 M, unaffected by NLA. Conclusions: MgSO4 relaxes canine MCA by a direct smooth muscle effect independent of the endothelium. Diphenylhydantoin causes an endothelium-dependent relaxation of canine MCA at concentrations above 3 10-5 M, unrelated to nitric oxide. MgSO4 and diphenylhydantoin may both help to prevent seizures in patients with eclampsia by reducing me potential for cerebral vasospasm.

KW - Cerebral vasospasm

KW - Diphenylhydantoin

KW - Magnesium sulfate

UR - http://www.scopus.com/inward/record.url?scp=0028350849&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028350849&partnerID=8YFLogxK

U2 - 10.3109/10641959409084171

DO - 10.3109/10641959409084171

M3 - Article

VL - 13

SP - 51

EP - 60

JO - Hypertension in Pregnancy

JF - Hypertension in Pregnancy

SN - 1064-1955

IS - 1

ER -