Abstract
OBJECTIVE: This study compared the effects of big endothelin-1, endothelin-1, and endothelin-3 and whether endothelin-converting enzyme was present in the human fetal-placental circulation. STUDY DESIGN: Single cotyledons of term placentas were dually perfused in vitro, and increases in fetal-placental perfusion pressure to bolus injections of big endothelin-1, endothelin-1, and endothelin-3 (8 × 10-10 to 1 × 10-7 mol/L) were recorded. Responses to big endothelin-1 (10-7 Mol/L) were measured in the same placenta before and after perfusion of the fetal-placental circulation with the neutral metalloprotease inhibitor phosphoramidon (10-5 mol/L), which acts as an endothelin-converting enzyme inhibitor. All experiments were performed in at least five separate placentas. RESULTS: Significant concentration-dependent increases in fetal-placental perfusion pressure were seen with endothelin-1 (p < 0.0005), endothelin-3 (p < 0.0256), and big endothelin-1 (p < 0.0034, analysis of variance). Big endothelin-1 always elicited transient vasodilatation before constriction. Phosphoramidon significantly inhibited the vasoconstrictor effect of big endothelin-1 (p < 0.039, paired t test). CONCLUSION: The three endothelins tested are vasoconstrictors, and endothelin-converting enzyme is present in the fetal-placental circulation.
Original language | English (US) |
---|---|
Pages (from-to) | 1651-1656 |
Number of pages | 6 |
Journal | American journal of obstetrics and gynecology |
Volume | 167 |
Issue number | 6 |
DOIs | |
State | Published - Dec 1992 |
Externally published | Yes |
Keywords
- Endothelin
- fetus
- placenta
- vasoconstriction
ASJC Scopus subject areas
- Obstetrics and Gynecology