Premium
Mechanisms underlying the reduced endothelium‐dependent relaxation in human omental resistance artery in pre‐eclampsia
Author(s) -
Suzuki Yoshikatsu,
Kajikuri Junko,
Suzumori Kaoru,
Itoh Takeo
Publication year - 2000
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.2000.00163.x
Subject(s) - contraction (grammar) , endocrinology , medicine , sodium nitroprusside , nitric oxide , endothelium , bradykinin , chemistry , eclampsia , preeclampsia , thromboxane a2 , biology , pregnancy , platelet , receptor , genetics
1 In pre‐eclampsia, a functional change occurs in the role played by endothelium‐derived nitric oxide (NO) in the regulation of smooth muscle contraction in resistance arteries. We investigated the underlying mechanism in human omental resistance arteries from normotensive pregnant and pre‐eclamptic women in the presence of diclofenac (an inhibitor of cyclo‐oxygenase). 2 In endothelium‐intact strips, the sensitivity to 9,11‐epithio‐11,12‐methano‐thromboxane A 2 (STA 2 ) was significantly higher in pre‐eclampsia, and this was not modified by either N G ‐nitro‐ l ‐arginine ( l ‐NNA, an inhibitor of NO synthase) or removal of the endothelium. 3 Bradykinin and substance P each produced an endothelium‐dependent relaxation of the STA 2 ‐induced contraction in both groups, although the relaxation was significantly smaller for pre‐eclampsia. l ‐NNA markedly attenuated the endothelium‐dependent relaxation in the normotensive pregnant group but not in the pre‐eclamptic group. 4 In the presence of l ‐NNA, the relaxation induced by sodium nitroprusside (SNP) on the STA 2 contraction was significantly smaller for pre‐eclamptic than for normotensive pregnant women. 5 In endothelium‐denuded strips, the relaxation induced by 8‐ para ‐ chlorophenyl thio‐guanosine‐3′,5′‐cyclic monophosphate (8‐pCPT‐cGMP) on the STA 2 contraction was significantly less for pre‐eclampsia. 6 In β‐escin‐skinned strips from both groups of women, 8‐pCPT‐cGMP (1–10 μ m ) concentration‐dependently attenuated the contraction induced by 0.5 μ m Ca 2+ . However, its relaxing action was significantly weaker in pre‐eclampsia. 7 It is suggested that the weaker responsiveness to NO seen in strips from pre‐eclamptic women may be partly due to a reduced smooth muscle responsiveness to cyclic GMP.