Fetoplacental vascular tone during fetal circuit acidosis and acidosis with hypoxia in the ex vivo perfused human placental cotyledon
| Autor: | Nathan J. Hoeldtke, Katherine H. Moore, Roderick F. Hume, Peter G. Napolitano, Byron C. Calhoun |
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| Rok vydání: | 1997 |
| Předmět: |
medicine.medical_specialty
Placental cotyledon Placenta Blood Pressure Fetal Hypoxia Nitric Oxide Fetus Pregnancy Internal medicine Renin–angiotensin system medicine Humans Acidosis business.industry Angiotensin II Obstetrics and Gynecology Hydrogen-Ion Concentration Hypoxia (medical) Perfusion Blood pressure Endocrinology Female medicine.symptom business |
| Zdroj: | American Journal of Obstetrics and Gynecology. 177:1088-1092 |
| ISSN: | 0002-9378 |
| DOI: | 10.1016/s0002-9378(97)70020-6 |
| Popis: | Objectives: Our purpose was to determine the effects of acidosis and acidosis-hypoxia on fetoplacental perfusion pressure and its response to angiotensin II. Study Design: Perfused cotyledons from 14 placentas were studied with either an acidotic fetal circuit perfusate ( n = 7) or an acidotic-hypoxic fetal circuit perfusate ( n = 7). Each cotyledon's fetal vasculature was initially perfused under standard conditions and bolus injected with 1 × 10 –10 moles of angiotensin II. Fetoplacental perfusate was then replaced with either an acidotic medium (pH 6.90 to 7.00 and Po 2 516 to 613 mm Hg) or an acidotic-hypoxic medium (pH 6.90 to 7.00 and Po 2 20 to 25 mm Hg) followed by an angiotensin II injection. The vasculature was subsequently recovered with standard perfusate and again injected with angiotensin II. Perfusion pressures within each group were compared by one-way analysis of variance, and results were expressed as mean pressure ± SEM. Results: Resting fetoplacental perfusion pressure did not change when the fetal circuit perfusate was made acidotic (28 ± 1 mm Hg vs 25 ± 2 mm Hg) or acidotic-hypoxic (26 ± 2 mm Hg vs 25 ± 2 mm Hg). The maximal fetoplacental perfusion pressure achieved in response to angiotensin II did not differ with an acidotic perfusate (41 ± 2 mm Hg vs 38 ± 1 mm Hg) or with an acidotic-hypoxic perfusate (39 ± 2 mm Hg vs 36 ± 2 mm Hg). Conclusions: In the perfused placental cotyledon fetoplacental perfusion pressure and pressor response to angiotensin II are not affected by fetal circuit acidosis or acidosis-hypoxia. This suggests that neither fetal acidosis nor fetal acidosis combined with hypoxia has a direct effect on fetoplacental vascular tone. |
| Databáze: | OpenAIRE |
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