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PLACENTAL HEME OXYGENASE ACTIVITY REDUCTION IS ASSOCIATED WITH HYPERTENSION IN PREGNANT RATS
Author(s) -
Llinás María Teresa,
Volti Giovanni Li,
Reverte Virginia,
Salazar Francisco,
Sáez Fara,
Salazar Francisco Javier
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1210.10
Subject(s) - endocrinology , heme oxygenase , medicine , placenta , gestation , preeclampsia , blood pressure , fetus , perfusion , heme , chemistry , pregnancy , biology , biochemistry , enzyme , genetics
Reduction in the placental perfusion pressure has long been thought to underlie preeclampsia (PE). It has also been demonstrated that inhibition of heme oxygenase (HO) activity in isolated placenta increases placental perfusion pressure. This finding suggests that the HO‐CO system is involved in regulating blood flow to this organ. However, it is unknown whether the reduction of placental HO activity produces hypertension during gestation, which is a common feature in PE. Therefore, the aim of this study was to determine whether administration of an HO inhibitor during gestation induces an elevation in blood pressure (BP) and whether the hypertension is associated to a reduced placental HO activity. The HO inhibitor, stannous mesoporphyrin (SnMP; 50 micromol/kg i.p) or vehicle (sodium carbonate) were administered to virgin (n=6) and pregnant rats (n=7) at day 14 of gestation. BP was measured 5 days later in conscious rats. SnMP increased (p<0.01) BP in pregnant rats (114 ± 1 vs 100 ± 2 mmHg) but had no effect in virgin rats (121 ± 2 vs 124 ± 3 mmHg). This increase was associated to a reduction in placental HO activity (10.4 ± 0.5 vs 6.9 ± 0.2 ng/bilirubin/μg protein/h, p<0.05) and an important fetal reabsorption (4.0 ± 0.7 vs 1.0 ± 0.3, p<0.05), indicating possible placental ischemia. These results suggest that the HO‐CO system may play an important role in the development of PE.