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Войти в исследования Journal of the Society for Gynecologic Investigation · 1997
Arginine vasopressin-induced changes in blood flow to the ovine chorion, amnion, and placenta across gestation.
Сравнительное исследованиеСтатьяПоддержка службы здравоохранения СШАНазвание и аннотация: Перевод в очереди
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Hedriana H L, Gilbert W M, Brace R A
Аннотация
OBJECTIVES: To determine whether physiological increases in fetal plasma arginine vasopressin (AVP) concentration alter blood flow rates to the ovine chorion, amnion or placenta, and to determine whether these AVP-induced changes in flow are dependent on gestational age.
METHODS: Colored microspheres (15.10 +/- 0.02 microns (standard deviation) were infused into the superior vena cava before and at 30, 75, and 125 minutes of an intravenous AVP infusion (3 ng/min/kg) in 9 chronically catheterized fetal sheep between 103 days to 141 days gestation (term = 147 days). Chorion, amnion, and placental cotyledons were removed, and microspheres were counted to determine blood flow rates.
RESULTS: Fetal arterial pressure (FAP) increased (analysis of variance, P < .0001) and heart rate (FHR) decreased (P < .0001) during the infusion, with responses greater in older (> 125 days) compared to younger (< 125 days) fetuses (P < .001). Chorionic blood flow rate increased by 19 +/- 7% at 30 min of the AVP infusion, and declined by 18 +/- 6% at 75 min, and 32 +/- 5% at 125 min (P < .0001). Similarly, fetal placental blood flow rate increased by 20 +/- 7% at 30 min of infusion, and declined, in parallel with chorionic blood flow rates, by 6 +/- 4% at 75 min, and 17 +/- 4% at 125 min (P < .0001). Amniotic blood flow rate did not change significantly during the infusion. The membranous and placental blood flow rate responses to AVP infusion did not depend upon gestational age.
CONCLUSIONS: Physiologic increases in plasma AVP concentration induce an early increase in chorionic blood flow followed by a gradual decrease which parallels similar changes in placental blood flow rate. Unlike FAP and FHR, these blood flow changes are not gestational age-dependent. AVP-induced blood flow changes could play an important role in determining abnormalities of amniotic fluid volume observed clinically in some stressed fetuses.
METHODS: Colored microspheres (15.10 +/- 0.02 microns (standard deviation) were infused into the superior vena cava before and at 30, 75, and 125 minutes of an intravenous AVP infusion (3 ng/min/kg) in 9 chronically catheterized fetal sheep between 103 days to 141 days gestation (term = 147 days). Chorion, amnion, and placental cotyledons were removed, and microspheres were counted to determine blood flow rates.
RESULTS: Fetal arterial pressure (FAP) increased (analysis of variance, P < .0001) and heart rate (FHR) decreased (P < .0001) during the infusion, with responses greater in older (> 125 days) compared to younger (< 125 days) fetuses (P < .001). Chorionic blood flow rate increased by 19 +/- 7% at 30 min of the AVP infusion, and declined by 18 +/- 6% at 75 min, and 32 +/- 5% at 125 min (P < .0001). Similarly, fetal placental blood flow rate increased by 20 +/- 7% at 30 min of infusion, and declined, in parallel with chorionic blood flow rates, by 6 +/- 4% at 75 min, and 17 +/- 4% at 125 min (P < .0001). Amniotic blood flow rate did not change significantly during the infusion. The membranous and placental blood flow rate responses to AVP infusion did not depend upon gestational age.
CONCLUSIONS: Physiologic increases in plasma AVP concentration induce an early increase in chorionic blood flow followed by a gradual decrease which parallels similar changes in placental blood flow rate. Unlike FAP and FHR, these blood flow changes are not gestational age-dependent. AVP-induced blood flow changes could play an important role in determining abnormalities of amniotic fluid volume observed clinically in some stressed fetuses.