Cyclooxygenase-1 and -2 in human placenta and placental bed after normal and pre-eclamptic pregnancies

Hum Reprod. 1997 Oct;12(10):2313-20. doi: 10.1093/humrep/12.10.2313.

Abstract

In pre-eclampsia, the ratio of prostacyclin:thromboxane production rate is decreased favouring the vasoconstrictive thromboxane. One of the rate-limiting steps in prostaglandin synthesis is cyclooxygenase (COX) activity. Therefore, we investigated the expression of COX-1 and COX-2 in human placenta and placental bed. Tissue specimens from the 29th to 40th week of pregnancy were obtained from Caesarean sections after uncomplicated and pre-eclamptic pregnancies before the onset of labour. COX-1 and COX-2 were localized immunohistochemically with the identification of positive cells by double immunofluorescence staining. The protein and mRNA levels were analysed by immunoblotting and quantitative reverse transcriptase-polymerase chain reaction. Expression of both COX-1 and COX-2 could be observed in placenta and placental bed. COX-1-like immunoreactivity was observed in most cell types with strongest staining in macrophages. Only macrophages, endothelium, vascular leiomyocytes and fibroblasts stained positively for COX-2. In placenta, COX-1 and -2 expression was unchanged after pre-eclampsia. In placental bed, protein and mRNA levels of COX-1 were increased in the pre-eclamptic group (P < 0.05), whereas COX-2 expression did not differ significantly from normal pregnancies. An increased expression of COX-1 could be involved in the pathophysiology of pre-eclamptic changes within the placental bed. A therapy with drugs inhibiting COX-1 might be beneficial in this condition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cyclooxygenase 1
  • Cyclooxygenase 2
  • Decidua / enzymology
  • Endothelium, Vascular / enzymology
  • Female
  • Fibroblasts / enzymology
  • Humans
  • Immunohistochemistry
  • Isoenzymes / analysis*
  • Isoenzymes / genetics
  • Macrophages / enzymology
  • Membrane Proteins
  • Muscle, Smooth / enzymology
  • Placenta / enzymology*
  • Pre-Eclampsia / enzymology*
  • Pregnancy
  • Prostaglandin-Endoperoxide Synthases / analysis*
  • Prostaglandin-Endoperoxide Synthases / genetics
  • RNA, Messenger / analysis
  • Trophoblasts / enzymology

Substances

  • Isoenzymes
  • Membrane Proteins
  • RNA, Messenger
  • Cyclooxygenase 1
  • Cyclooxygenase 2
  • PTGS1 protein, human
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases