Abstract
Leukotrienes are synthesized during pregnancy and produce cardiovascular effects in adults. We hypothesized that leukotriene C4 would cause vasoconstriction in the fetus and placenta. Eight near-term, unanesthetized ovine fetuses were studied before and after infusion of 10 μg leukotriene C4 (LTC4) into the fetal vena cava. Cardiovascular monitoring of maternal and fetal arterial pressures and heart rates was performed. Fetal blood flows were measured by the radioactive-microsphere technique. Sustained elevations in systolic and diastolic blood pressure and decreased fetal heart rate began by 1 min and returned to baseline by 30 min. Arterial pH fell from 7.33 ± 0.01 to 7.29 ± 0.01 at 15 min (P < 0.05) and to 7.29 ± 0.01 at 30 min (P < 0.05), with a significant increase in base deficit from 0.7 ± 0.7 to 3.5 ± 0.7 at 15 min (P < 0.05) and to 2.9 ± 1.0 at 30 min (P < 0.05). Fetal PO2 and PCO2 were unchanged. Signifcant decreases in blood flow and resistance were seen in the umbilical placental circulation as well as in fetal skeletal muscle and intestine. Blood flow and resistance were unchanged in the renal and adrenal vascular beds. Fetal administration of LTC4 caused no changes in maternal cardiovascular parameters. These findings represent the first in vivo studies of the effects of a lipoxygenase metabolite on fetal-placental blood flow.
Original language | English (US) |
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Pages (from-to) | E851-E855 |
Journal | American Journal of Physiology - Endocrinology and Metabolism |
Volume | 259 |
Issue number | 6 22-6 |
DOIs | |
State | Published - 1990 |
Keywords
- fetal blood flow
- radioactive microspheres
- umbilical placental blood flow
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Physiology
- Physiology (medical)