Disease relevance of Placental Circulation

• OBJECTIVE: To determine the effects of nitroglycerin on placental circulation in severe preeclampsia [1].
• Nitric oxide-mediated vascular tone in the fetal placental circulation of patients with type 1 diabetes mellitus [2].
• Doppler assessment of the fetal and uteroplacental circulation during nifedipine therapy for preterm labor [3].
• To investigate the role of phosphatidylserine (PS) derived from the activated platelets in placental circulation, we established an artificial PS-induced intrauterine growth restriction (IUGR) model in mice and examined whether annexin V, a PS-binding anticoagulant protein, could prevent the development of IUGR in the animal experiments [4].
• These results suggest that hypoxia due to the persistence of placental circulation results in an increase in lactiacidemia as a consequence of a decrease in lactate utilization [5].

High impact information on Placental Circulation

• Effect of allyloestrenol on deteriorating uteroplacental circulation [6].
• In the normal placenta NO is generated only by endothelial NOS, which apparently serves to regulate vascular tone in the fetoplacental circulation [7].
• During pregnancy, CRH and CRH-related peptides appear to regulate the fetoplacental circulation via activation of the nitric oxide (NO)/cGMP pathway [8].
• We hypothesized that NKB is a paracrine modulator of tone in the fetal placental circulation [9].
• In pathological pregnancies, alterations in circulating maternal and fetal adrenomedullin (ADM) concentrations may mediate compensatory vascular responses in the fetal or placental circulation [10].

Chemical compound and disease context of Placental Circulation

• We aimed to investigate the effect of NAC on the NO-pathway in the human fetoplacental circulation in preeclampsia and control pregnancies [11].
• CONCLUSIONS: Long-term transdermal administration of isosorbide dinitrate improves fetoplacental circulation and may be effective therapy for avoiding maternal hypertension and oligohydramnios in some preeclamptic women [12].
• Endothelin, a vasoconstrictor important to the uteroplacental circulation in pre-eclampsia [13].
• Labetalol therapy in pregnancy induced hypertension: the effects on fetoplacental circulation and fetal outcome [14].

Biological context of Placental Circulation

• Corticotropin-releasing hormone-induced vasodilatation in the human fetal placental circulation [15].
• These results indicate that CRH has powerful vasodilator properties in the human fetal-placental circulation and may play a role in control of placental vascular resistance to blood flow [15].
• Serotonin-induced vasoconstriction is mediated by thromboxane release and action in the human fetal-placental circulation [16].
• These results suggest that retarded fetal growth in heavy smokers is due to impairment of uteroplacental circulation as a result of the vasoconstricting effect of nicotine [17].
• Our objectives were to determine: 1) whether angiotensin II (ANG II) acts as a vasodilator or purely as a vasoconstrictor in the uteroplacental circulation, and 2) whether this circulation is capable of autoregulation [18].

Anatomical context of Placental Circulation

• Maternal cell trafficking into scid/scid fetuses commenced about midgestation, coincident with maturation of a placental circulation [19].
• Thus, a fetal artery and a fetal vein were cannulated and perfused with pure medium (fetoplacental circulation), whereas the intervillous space of placentas was flushed with allergen containing medium by puncture of the basal plate (maternoplacental circulation) [20].
• CONCLUSION: The polyamines spermine and spermidine exert a potent relaxant effect on human umbilical artery tone suggestive of an endogenous role for these compounds in vasomotor regulation of the fetoplacental circulation [21].
• In addition to our standard protocol (magnesium, glucose, betamethasone), each patient received an epidural catheter (T10/T12) with continuous infusion of bupivacaine 0.175% at a rate of 5 ml/h. Uteroplacental circulation was monitored by Doppler sonography and the amount of amniotic fluid was estimated daily [22].
• By interfering with ACh release and placental blood flow, the three drugs of abuse may depress the diffusion of amino acids and other nutrients from the trophoblast into the placental circulation [23].

Associations of Placental Circulation with chemical compounds

• ACTH was 187.4 (95% confidence limits, 162.7-215.9) times more potent than prostacyclin (PGI2; 1.2-1180 nmol/L; n = 6), which is a known vasodilator of the fetal-placental circulation [24].
• These data suggest that dexamethasone can cause dilation in the fetal-placental circulation, possibly via an endothelium-independent pathway [25].
• Infusion of sodium nitroprusside (30-100 mumol/L) into the maternal and fetal placental circulations inhibited CRH-IR release into maternal perfusate in a concentration-dependent manner, but did not inhibit CRH-IR release into the fetal perfusate [26].
• Neurokinin B is a paracrine vasodilator in the human fetal placental circulation [9].
• Corticotropin-releasing hormone-induced vasodilatation in the human fetal-placental circulation: involvement of the nitric oxide-cyclic guanosine 3',5'-monophosphate-mediated pathway [27].

Gene context of Placental Circulation

• The production of vascular endothelial growth factor (VEGF) family molecules is confirmed in placental cells including CTs, but it is not elucidated how the VEGF system in CTs is controlled by oxygen tension and how it is involved in the development of placental circulation [28].
• CONCLUSIONS: These results demonstrate the vasodilator effects of CGRP, PTH, and PTHrP in the human fetal-placental circulation [29].
• The presence of CGRP and NPY suggests the involvement of these peptides in the regulation of the umbilical and placental circulation [30].
• These findings support the idea that ETs, through interaction with ETA and ETB receptors, play an important role in the regulation of placental growth and fetoplacental circulation through autocrine and paracrine mechanisms [31].
• CGRP is a potent vasodilator with increased levels in fetoplacental circulation during late pregnancy [32].

Analytical, diagnostic and therapeutic context of Placental Circulation

• Neither acetylcholine nor the calcium ionophore A23187 had an effect on the fetal-placental circulation, whereas bradykinin further increased perfusion pressure [33].
• Venous constriction to U46619 and relaxation to sodium nitroprusside were modified by adjustment of media oxygen tension and normalization parameters.Human placental chorionic plate veins respond to vasoactive agents and may play a role in the control of the blood flow in the fetoplacental circulation [34].
• To test the hypothesis that prostacyclin dilates the fetal placental circulation in vivo, we measured blood flow by the radioactive microsphere technique in six unanesthetized near-term ovine fetuses before and during prostacyclin infusion [35].
• Doppler ultrasound of the uteroplacental circulation in the prediction of pregnancy outcome in women with raised maternal serum alpha-fetoprotein [36].
• RESULTS: Increasing the frequency of plasma-exchange therapy prevented the extreme serum cholesterol elevation that occurs in pregnant HFH patients and was associated with a significant improvement in uteroplacental circulation [37].

References