Open AccessEffect of nitric oxide, prostacyclin, and thromboxane on the vasospastic action of hydrogen peroxide on human umbilical artery
Author(s) -
Okatani Yuji,
Watanabe Kazushi,
Sagara Yusuke
Publication year - 1997
Publication title -
acta obstetricia et gynecologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.401
H-Index - 102
eISSN - 1600-0412
pISSN - 0001-6349
DOI - 10.3109/00016349709024575
Subject(s) - prostacyclin , medicine , nitric oxide , hydrogen peroxide , umbilical artery , thromboxane , thromboxane a2 , vasodilation , anesthesia , pharmacology , cardiology , platelet , pregnancy , biochemistry , chemistry , biology , genetics , fetus
Background. The effect of hydrogen peroxide (H 2 O 2 ) on vascular tone in the human umbilical artery was investigated to determine the mechanism of vasospasm in preeclampsia. Methods. Helical sections of the umbilical artery were obtained from healthy pregnant women who delivered between the 37th and 39th week of gestation. Changes in the maximal tension induced by prostaglandin F 2 α (PG F 2 α) were measured (isometric mechanical activity). Segments were treated with H 2 O 2 alone or H 2 O 2 after pretreatment with a scavenger of hydroxyl radicals (mannitol), an inhibitor of thromboxane synthesis (sodium ozagrel), and an inhibitor of nitric oxide synthesis (L‐N G ‐monomethyl arginine, LNMA), or an inhibitor of prostacyclin synthesis (tranylcypromine, TCP). Results. Vascular tension was potentiated by H 2 O 2 in a concentration‐dependent manner. Pretreatment with mannitol significantly suppressed the vasospastic effect of H 2 O 2 . Removal of the endothelium decreased the vascular tension induced by H 2 O 2 . Treatment with TCP and LNMA potentiated the vascular tension. Pretreatment with TCP and LNMA reduced the vasospastic action of H 2 O 2 , whereas pretreatment with sodium ozagrel did not. Conclusion. Vascular tension in human umbilical arteries was potentiated by H 2 O 2 , and may be mediated by a suppression of the activity of nitric oxide or of prostacyclin. A direct action of H 2 O 2 on vascular smooth muscle may also be involved.