Open AccessPotentiating effect of hydrogen peroxide on the serotonin‐induced vasocontraction in human umbilical artery
Author(s) -
Watanabe Kazushi,
Okatani Yuji,
Sagara Yusuke
Publication year - 1996
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 - 10.3109/00016349609054704
Subject(s) - hydrogen peroxide , serotonin , medicine , endocrinology , umbilical artery , calcium , vasodilation , contraction (grammar) , chemistry , receptor , biochemistry , biology , fetus , pregnancy , genetics
Background. Our objective was to investigate the role of hydrogen peroxide in the vasocontraction induced in the human umbilical artery by serotonin. Methods. Umbilical arteries collected from healthy women at term were cut helically and suspended in an organ bath to record isometric mechanical activity. In Study I, we measured the concentration‐contraction response to serotonin with or without pretreatment with hydrogen peroxide (0.01 ˜ 10 μM). In Study 2, vessels were pre‐incubated with L‐arginine (0.1 ˜ 10 mM), or with hydrogen peroxide (10 mM) and L‐arginine (1 mM), then serotonin was added cumulatively. In Study 3, vessels were suspended in a calciuim‐free solution containing potassium chloride 20 mM, and a cumulative concentration‐response curve to calcium chloride (10 −5 ˜ 10 −3 M) was constructed for vessels pretreated with hydrogen peroxide (10 μM). In Study 4, vessels were pre‐treated with M 1 , an inhibitor of 5‐HT 2 serotoninergic receptors, and hydrogen peroxide (10 μM), and then prostaglandin F 2α (9.0±10 −7 M). Finally, we measured the 5‐HT 1 receptor‐mediated relaxation induced by serotonin. Results. Hydrogen peroxide (1 or 10 μM) significantly potentiated the contractile response to serotonin ( p <0.04, p <0.005). L‐arginine (1 or 10 mM) significantly reduced the contractile response to serotonin ( p <0.02, p <0.0002). Pretreatment with L‐arginine significantly suppressed the potentiating effect of hydrogen peroxide on the serotonin‐induced contraction. The sensitivity of the arteries to calcium chloride in the presence of hydrogen peroxide did not differ from that in the control group. Pretreatment with hydrogen peroxide significantly reduced the 5‐HT, serotoninergic receptor‐mediated relaxation at higher concentrations of serotonin (1.23±10 −4 M, 2.47±10 −4 M, 2.47±10 −4 M). Conclusion. Hydrogen peroxide potentiated the umbilical artery contraction induced by serotonin. This action may be mediated by suppression of endogenous nitric oxide activity.