Pre-eclampsia and Fetal Growth Restriction: How Morphometrically Different is the Placenta?

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• 作者：M. Egbor ; T. Ansari ; N. Morris ; C.J. Green ; P.D. Sibbons
• 关键词：Fetal growth restriction (FGR) ; Pre-eclampsia (PET) ; Placental morphology ; Stereology
• 刊名：Placenta
• 出版年：2006
• 出版时间：June-July 2006
• 年：2006
• 卷：27
• 期：6-7
• 页码：727-734
• 全文大小：278 K

文摘

Unlike all vascular beds with the exception of the pulmonary circulation, fetoplacental vessels respond to acute hypoxia with vasoconstriction. While this hypoxic fetoplacental vasoconstriction (HFPV) is considered essential in the pathogenesis of intrauterine growth retardation, its mechanism is largely unknown. Hypoxia inhibits potassium channels and thus causes depolarization in fetoplacental vascular smooth muscle. We propose that this hypoxia-induced depolarization leads to vasoconstriction by activating voltage-dependent calcium (Ca) channels and Ca influx. We compared HFPV between isolated perfused human cotyledons treated with an inhibitor of L-type channels, nifedipine, and preparations receiving only vehicle. While the solvent (diluted DMSO) had no inhibitory effect on HFPV, the hypoxic responses were completely abolished even by a relatively low dose of nifedipine (1 nM). We conclude that activation of L-type Ca channels is an essential part of HFPV.