scholarly journals Placental Transfer of Lactate, Glucose and 2-deoxyglucose in Control and Diabetic Wistar Rats

2001 ◽  
Vol 2 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Chris R. Thomas ◽  
Beryl B. Oon ◽  
Clara Lowy
Keyword(s):  
Blood Flow ◽  
Wistar Rats ◽  
Placental Transfer ◽  
Maternal Plasma ◽  
Diabetic Group ◽  
Control Group ◽  
Placental Blood ◽  
Lactate Levels ◽  
Placental Blood Flow

Placental transfer of lactate, glucose and 2-deoxyglucose was examined employing thein situperfused placenta. Control and streptozotocin induced diabetic Wistar rats were infused with U-14C]-glucose and [3H]-2-deoxyglucose (2DG). The fetal side of the placenta was perfuseci with a cell free medium and glucose uptake was calculated in the adjacent fetuses. Despite the 5-fold higher maternal plasma glucose concentration in the diabetic dams the calculated fetal glucose metabolic index was not significantly different between the 2 groups. Placental blood flow was reduced in the diabetic animals compared with controls but reduction of transfer of [U-14C]-glucose and [3H]-2-deoxyglucose and endogenously derived [14C]-Lactate to the fetal compartment, could not be accounted for by reduced placental blood flow alone. There was no significant net production or uptake of lactate into the perfusion medium that had perfused the fetal side of the placenta in either group. The plasma lactate levels in the fetuses adjacent to the perfused placenta were found to be higher than in the maternal plasma and significantly higher in the fetuses of the diabetic group compared with control group. In this model thein situperfused placenta does not secrete significant quantities of lactate into the fetal compartment in either the control or diabetic group.

Chronic alterations in ovine maternal corticosteroid levels influence uterine blood flow and placental and fetal growth

2005 ◽  
Vol 288 (1) ◽  
pp. R54-R61 ◽  
Author(s):  
Ellen Jensen ◽  
Charles E. Wood ◽  
Maureen Keller-Wood
Keyword(s):  
Blood Flow ◽  
Plasma Cortisol ◽  
Somatic Growth ◽  
Maternal Plasma ◽  
Control Group ◽  
Uterine Blood Flow ◽  
Arterial Blood ◽  
Placental Blood ◽  
Low Cortisol ◽  
Placental Blood Flow

Previous work from this laboratory demonstrated that the elevation of maternal plasma corticosteroid concentrations during pregnancy is important for the support of fetal development. Reducing ovine maternal plasma cortisol concentrations to nonpregnant levels stimulates homeostatic responses that defend fetal blood volume. The present study was designed to test the hypothesis that chronic decreases or increases in maternal plasma cortisol concentration alter uterine and placental blood flow and morphology. Three groups of pregnant ewes and their fetuses were chronically catheterized and studied: ewes infused with cortisol (1 mg·kg−1·day−1; high cortisol), ewes adrenalectomized and underreplaced with cortisol (0.5 mg·kg−1·day−1; low cortisol), and control ewes. The normal increment in uterine blood flow between 120 and 130 days was eliminated in the low-cortisol ewes; conversely, uterine blood flow was increased in the high-cortisol group compared with the control group. Fetal arterial blood pressure was increased in the high-cortisol group compared with controls, but there was no increase in fetal arterial pressure from 120 to 130 days of gestation in the low-cortisol group. The fetuses of both low-cortisol and high-cortisol groups had altered placental morphology, with increased proportions of type B placentomes, and overall reduced fetal placental blood flow. The rate of fetal somatic growth was impaired in both low-cortisol and high-cortisol groups compared with the fetuses in the intact group. The results of this study demonstrate that maternal plasma cortisol during pregnancy is an important contributor to the maternal environment supporting optimal conditions for fetal homeostasis and somatic growth.

Fetal sheep endocrine responses to sustained hypoxemic stress after chronic fetal placental embolization

1997 ◽  
Vol 272 (5) ◽  
pp. E817-E823 ◽  
Author(s):  
R. Gagnon ◽  
J. Murotsuki ◽  
J. R. Challis ◽  
L. Fraher ◽  
B. S. Richardson
Keyword(s):  
Blood Flow ◽  
Oxygen Content ◽  
Regional Distribution ◽  
Arterial Oxygen ◽  
Control Group ◽  
Fetal Sheep ◽  
Arterial Oxygen Content ◽  
Placental Blood ◽  
Chronic Hypoxemia ◽  
Placental Blood Flow

The purpose of this study was to determine the endocrine and circulatory responses of the ovine fetus, near term, to sustained hypoxemic stress superimposed on chronic hypoxemia. Fetal sheep were chronically embolized (n = 7) for 10 days between 0.84 and 0.91 of gestation via the descending aorta until arterial oxygen content was decreased by approximately 30%. Control animals (n = 8) received saline only. On experimental day 10, both groups were embolized over a 6-h period until fetal arterial pH decreased to approximately 7.00. Regional distribution of lower body blood flows was measured on day 10, before and at the end of acute embolization. On day 10, the chronically embolized group had lower arterial oxygen content (P < 0.05), Po2 (P < 0.01), and placental blood flow (P < 0.05) than controls and higher prostaglandin E2 (PGE2) and norepinephrine plasma concentrations (both P < 0.05). In response to a superimposed sustained hypoxemic stress, there was a twofold greater increase in PGE2 in the chronically embolized group than in the control group (P < 0.05). However, the increase in fetal plasma cortisol in response to superimposed hypoxemic stress was similar in both groups, despite significantly lower adrenocorticotropic hormone and adrenal cortex blood flow responses in the chronically hypoxemic group (both P < 0.05). We conclude that PGE2 response to a sustained superimposed reduction in placental blood flow, leading to metabolic acidosis, is enhanced under conditions of chronic hypoxemia and may play an important role for the maintenance of the fetal cortisol response to an episode of superimposed acute stress.

The effect of litter size on placental blood flow and placental calcium transfer in the multifoetate guinea-pig

1978 ◽  
Vol 39 (2) ◽  
pp. 347-356 ◽  
Author(s):  
H. W. Symonds ◽  
R. H. Bubar ◽  
W. CRACKEL ◽  
A. R. Twardock
Keyword(s):  
Blood Flow ◽  
Litter Size ◽  
Flow Rate ◽  
Transfer Rate ◽  
Placental Tissue ◽  
Blood Flow Rate ◽  
Maternal Plasma ◽  
Placental Blood ◽  
The Mean ◽  
Placental Blood Flow

1. Placental blood flow rate and calcium transfer rate were measured at 61 d of pregnancy in guinea-pigs carrying between one and eight foetuses.2. Placental blood flow rate was significantly correlated with foetal weight. Ca transfer rate was related to placental size. Irrespective of litter size the mean amount of Ca transferred across a placenta was between 0.22 and 0.34 mg/h per g placental tissue.3. It was concluded that there was a limit to the rate of transfer which was produced by a combination of limitations in placental blood flow rate, maternal plasma Ca concentration and placental tissue transfer capacity.

scholarly journals Estimation of the Functional Condition of a Fetus of Pregnancy in Chronic Pyelonephritis

2013 ◽  
Vol 68 (12) ◽  
pp. 80-82 ◽  
Author(s):  
Sh.G. Kadimova
Keyword(s):  
Blood Flow ◽  
Pregnant Women ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Umbilical Artery ◽  
Chronic Pyelonephritis ◽  
Performance Ratio ◽  
Control Group ◽  
Placental Blood ◽  
Placental Blood Flow

Aim of this study was to investigate the condition of the fetus and feto placental system in chronic pyelonephritis by identifying features in the feto- placental blood flow and middle cerebral artery system. Patients and methods.  We examined 68 pregnant women with chronic pyelonephritis and 50 healthy pregnant women as a control group . The study conducted a qualitative assessment of fetus and placental blood flow and blood flow in the middle cerebral artery of the fetus . The data on the condition of  feto- placental blood flow and blood flow in the middle cerebral artery in the examined pregnant and control group show a higher incidence of elevated systolic and diastolic performance ratio in the umbilical artery in patients with chronic pyelonephritis than somatically healthy women. Results. Studies have shown that the most accurate and informative indicator of violations feto- placental circulation is an increase in the umbilical artery  whose value ( 2.9 and above) reflects the high degree of suffering of the fetus on a background of chronic pyelonephritis. Conclusions. Diagnostically significant is the indicator of the middle cerebral artery blood flow, which reflects the mechanism of enhancement of cerebral circulation in chronic hypoxia due to violation of feto- placental circulation in patients with renal disease.Key words: placentary insufficiency, nephritic pathology, pregnancy.

scholarly journals Non-invasive evaluation of placental blood flow: lessons from animal models

Reproduction ◽  
2017 ◽  
Vol 153 (3) ◽  
pp. R85-R96 ◽  
Author(s):  
E Mourier ◽  
A Tarrade ◽  
J Duan ◽  
C Richard ◽  
C Bertholdt ◽  
...  
Keyword(s):  
Blood Flow ◽  
Animal Models ◽  
Ultrasound Contrast Agents ◽  
Valuable Insight ◽  
Non Invasive ◽  
Placental Blood ◽  
2D And 3D ◽  
Reliable Methods ◽  
Placental Blood Flow ◽  
Invasive Evaluation

In human obstetrics, placental vascularisation impairment is frequent as well as linked to severe pathological events (preeclampsia and intrauterine growth restriction), and there is a need for reliable methods allowing non-invasive evaluation of placental blood flow. Uteroplacental vascularisation is complex, and animal models are essential for the technical development and safety assessment of these imaging tools for human clinical use; however, these techniques can also be applied in the veterinary context. This paper reviews how ultrasound-based imaging methods such as 2D and 3D Doppler can provide valuable insight for the exploration of placental blood flow both in humans and animals and how new approaches such as the use of ultrasound contrast agents or ultrafast Doppler may allow to discriminate between maternal (non-pulsatile) and foetal (pulsatile) blood flow in the placenta. Finally, functional magnetic resonance imaging could also be used to evaluate placental blood flow, as indicated by studies in animal models, but its safety in human pregnancy still requires to be confirmed.

Effect of terbutaline sulphate on ovarian, uterine and maternal placental blood flow in the anaesthetized guinea pig

1978 ◽  
Vol 53 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Lena Mårtensson ◽  
Per-Ove B. Sjöquist ◽  
Leif Bjellin ◽  
Anthony M. Carter
Keyword(s):  
Blood Flow ◽  
Guinea Pig ◽  
Terbutaline Sulphate ◽  
Placental Blood ◽  
Placental Blood Flow

Fetal cardiac bypass alters regional blood flows, arterial blood gases, and hemodynamics in sheep

1992 ◽  
Vol 263 (3) ◽  
pp. H919-H928 ◽  
Author(s):  
S. M. Bradley ◽  
F. L. Hanley ◽  
B. W. Duncan ◽  
R. W. Jennings ◽  
J. A. Jester ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Gases ◽  
Arterial Blood Gases ◽  
Blood Flows ◽  
Arterial Blood ◽  
Cardiac Bypass ◽  
Regional Blood Flows ◽  
Placental Blood ◽  
Fetal Organs ◽  
Placental Blood Flow

Successful fetal cardiac bypass might allow prenatal correction of some congenital heart defects. However, previous studies have shown that fetal cardiac bypass may result in impaired fetal gas exchange after bypass. To investigate the etiology of this impairment, we determined whether fetal cardiac bypass causes a redistribution of fetal regional blood flows and, if so, whether a vasodilator (sodium nitroprusside) can prevent this redistribution. We also determined the effects of fetal cardiac bypass with and without nitroprusside on fetal arterial blood gases and hemodynamics. Eighteen fetal sheep were studied in utero under general anesthesia. Seven fetuses underwent bypass without nitroprusside, six underwent bypass with nitroprusside, and five were no-bypass controls. Blood flows were determined using radionuclide-labeled microspheres. After bypass without nitroprusside, placental blood flow decreased by 25–60%, whereas cardiac output increased by 15–25%. Flow to all other fetal organs increased or remained unchanged. Decreased placental blood flow after bypass was accompanied by a fall in PO2 and a rise in PCO2. Nitroprusside improved placental blood flow, cardiac output, and arterial blood gases after bypass. Thus fetal cardiac bypass causes a redistribution of regional blood flow away from the placenta and toward the other fetal organs. Nitroprusside partially prevents this redistribution. Methods of improving placental blood flow in the postbypass period may prove critical to the success of fetal cardiac bypass.

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