Uterine prostaglandin E secretion and uterine blood flow in the pregnant rabbit.

Venuto, Rocco C.; O'Dorisio, Thomas M.; Stein, Janice Gross; Ferris, Thomas F.

doi:10.1172/jci107911

Cited by 78 publications

(28 citation statements)

References 16 publications

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“…We have found that most fetal lambs survive for many days after mechanical closure of the ductus arteriosus. It is possible that the fetal deaths after maternal indomethacin administration are due to effects of prostaglandin synthesis inhibition other than closure of the ductus arteriosus such as the increase in uterine vascular resistance (32,33).…”

Section: Discussionmentioning

confidence: 99%

Ligating the Ductus Arteriosus before Birth Causes Persistent Pulmonary Hypertension in the Newborn Lamb

1989

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ABSTRACT. We determined whether closing the ductus arteriosus of the fetal lamb several d before birth would cause persistent pulmonary hypertension after birth. Six experimental fetuses who had their ductus arteriosus ligated 3-17 d before delivery, three control fetuses who had sham ligation of the ductus arteriosus 14 d before delivery, and six control fetuses who had no prenatal surgery were delivered by cesarean section between 138 and 144 d of gestation. Each was instrumented to measure pulmonary and systemic arterial pressures and pulmonary blood flow. Each newborn lamb was ventilated with room air during the first 45 min after birth and then with decreasing amounts of inspired oxygen from 108 to 9%. Pulmonary arterial pressure decreased significantly when ventilation was begun in the control lambs but not in the lambs who had their ductus arteriosus ligated before deliverv.Throughout the experiment, pulmonary arterial pressure and total pulmonary resistance were significantly higher, and pulmonary blood flow was significantly lower in the lambs who had their ductus arteriosus ligated before delivery. In two of them, pulmonary arterial pressure was greater than or equal to systemic arterial pressure, even during ventilation with 100% oxygen. This animal preparation provides a method of investigating persistent pulmonary hypertension in the newborn lamb and may provide insight into an etiology of the syndrome of persistent pulmonary hypertension of the newborn. (Pediatr Res 25:245-250,1989) sion? There are at least two major differences between the pulmonary circulation of the fetus and that of the adult during chronic hypoxia. In the fetus, right ventricular output is shunted away from the lungs across the ductus arteriosus (7, 8) and the peripheral, intraacinar arteries of the pulmonary ciruclation are not remodeled (9). Perhaps the diversion of right ventricluar output somehow protects the intraacinar arteries and prevents the development of persistent pulmonary hypertension (10, 1 1). There are reports of long-term survival of the fetus after closure of the ductus arteriosus (12, 13). We performed this study to determine whether closing the ductus arteriosus of the fetal lamb several d before birth would cause persistent pulmonary hypertension after birth. MATERIALS AND METHODSA total of 21 fetal lambs were used for this study. Term gestation in sheep is 146 d. Twelve experimental fetuses had their ductus arteriosus ligated when they were between 123 and 135 d of gestation, 3-17 d before delivery. Three control fetuses had sham ligation of the ductus arteriosus when they were 127 d of gestation, 14 d before delivery. Six control lambs had no surgery before delivery. Each surviving fetus was delivered between 138 and 144 d of gestation.Ligation and sham ligation of ductus arteriosus before delivery. Each of 15 pregnant ewes was induced into anesthesia with an intravenous injection of sodium thiamylal. Surgery was then performed under halothane anesthesia. The uterus was exvosed through a midline abdomin...

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Section: Discussionmentioning

confidence: 99%

Ligating the Ductus Arteriosus before Birth Causes Persistent Pulmonary Hypertension in the Newborn Lamb

1989

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“…Prostaglandin E was measured by radioimmunoassay utilizing a method previously reported (8 Initial samples were collected and the first microsphere injection was performed. Samples were collected and a second set of microspheres were injected after the pressure had stabilized at the hypotensive level.…”

Section: Methodsmentioning

confidence: 99%

The effect of changes in perfusion pressure on uteroplacental blood flow in the pregnant rabbit.

Venuto¹,

Cox²,

Stein³

et al. 1976

J. Clin. Invest.

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A B S T R A C T The effect of perfusion pressure on uteroplacental blood flow was determined in pregnant rabbits utilizing the radioactive microsphere method.Control mean arterial pressure, 93 mm Hg±2.6 SEM, was raised by carotid ligation to 109±4.1 mm Hg and then reduced with antihypertensive drugs to 74+1.3 mm Hg. Over this range of pressure there was no significant change in cardiac output, 605+36, 523+37, and 540±39 ml/min; or uteroplacental blood flow, 30+3.2, 27±5.2, and 29±4.5 ml/min, respectively. When prostaglandin synthesis was inhibited with either indomethacin or meclofenamate (2 mg/kg), uterine vascular resistance was higher but maintenance of uteroplacental flow occurred over a perfusion pressure of 89±6.7-115 +9.3 mm Hg. With more severe hypotension induced with trimethaphan, control arterial pressure fell from 92±2.4 to 39+0.9 mm Hg, cardiac output fell from 514 +17 to 407+22 ml/min (P < 0.025) and uteroplacental blood flow fell from 6.1±0.9 to 2.5±0.9% of cardiac output (P<0.05), which represented an absolute fall from 32.4±5 to 10.6±3 ml/min (P <0.025). There was no significant change in renal blood flow expressed as percentage of cardiac output, 14.9+2 and 13±1.5%, or in absolute flow, 75+77 and 54+7 ml/min with trimethaphan-induced hypotension.These studies indicate that uteroplacental blood flow is maintained relatively constant over a range of perfusion pressure of 60-140 mm Hg in both normal and prostaglandin-inhibited pregnant rabbits. However, with reduction in pressure to 36-42 mm Hg, uteroplacental blood flow falls, expressed as a percentage of cardiac output and in absolute flow.

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“…Some of these refl ect the generation of free arachidonic acid from phospholipids and its expected conversion to lipid signaling molecules, including prostaglandins, HETES, thromboxanes, and leukotrienes. Local circulation through capillaries is infl uenced by some of these, and in particular it is increased by prostaglandins of the E series [e.g., ( 52,53 )]. Given the graded response of iPLA 2 activity to decreasing membrane potential ( Fig.…”

Section: Downloaded Frommentioning

confidence: 99%

Regulation of the Ca -independent phospholipase A2 in liver mitochondria by changes in the energetic state

Rauckhorst

Broekemeier

Pfeiffer

2014

Journal of Lipid Research

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Uterine prostaglandin E secretion and uterine blood flow in the pregnant rabbit.

Cited by 78 publications

References 16 publications

Ligating the Ductus Arteriosus before Birth Causes Persistent Pulmonary Hypertension in the Newborn Lamb

Ligating the Ductus Arteriosus before Birth Causes Persistent Pulmonary Hypertension in the Newborn Lamb

The effect of changes in perfusion pressure on uteroplacental blood flow in the pregnant rabbit.

Regulation of the Ca -independent phospholipase A2 in liver mitochondria by changes in the energetic state

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