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Updated: Jul 5, 2026
11:59
In Vivo Real-Time Study of Drug Effects on Carotid Blood Flow in the Ovine Fetus
Published on: April 28, 2023
Foetal vascular responses to thromboxane receptor blockade
B A Meyer1, J E Dickinson, S W Walsh
1Department of Obstetrics, Gynecology and Reproductive Sciences and Departments of Pediatrics, Physiology and Cell Biology University of Texas Medical School Houston USA.
Mediators of Inflammation
|January 1, 1992
Summary
SQ-29,548, a thromboxane receptor blocker, prevented vasoconstriction in fetal sheep but caused reduced blood flow and pressure. Further research is needed to assess its safety for treating pregnancy disorders.
Area of Science:
- Obstetrics and Gynecology
- Perinatology
- Pharmacology
Background:
- Pregnancy complications can involve placental vasoconstriction.
- Thromboxane mimics are implicated in causing vasoconstriction.
- Thromboxane receptor blockers are potential therapeutic agents.
Purpose of the Study:
- To investigate the effect of fetal administration of SQ-29,548 on U46619-induced foeto-placental vasoconstriction.
- To evaluate the safety and efficacy of SQ-29,548 in a ovine model.
Main Methods:
- Chronic catheterization of pregnant ewes.
- Continuous monitoring of maternal and fetal vital signs.
- Measurement of fetal blood flow and vascular resistance using radioactive microspheres.
- Administration of SQ-29,548 and U46619.
Main Results:
- SQ-29,548 successfully blocked thromboxane-induced vasoconstriction.
- Prolonged SQ-29,548 infusion led to decreased umbilical-placental blood flow.
- Fetal mean arterial pressure and acid-base balance were negatively impacted.
Conclusions:
- While SQ-29,548 blocks thromboxane effects, its intrinsic vasoactive properties require further study.
- Potential therapeutic use of SQ-29,548 for pregnancy vasoconstrictive disorders is uncertain.
- More research is needed on SQ-29,548's impact on the umbilical-placental vasculature.
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