Ergot alkaloid consumption alters serotonin receptor-induced vasoactivity in ovine umbilical vasculature.

Consumption of ergot alkaloids during the second half of gestation has been shown to decrease umbilical artery vasoactivity resulting in decreased birth weights. Negative vascular effects of ergot alkaloids are mediated predominantly through serotonergic and adrenergic receptors in other tissues. Vasoactivity of serotonin (5-HT) receptors 5-HT2A and 5-HT1B/1D in umbilical artery and vein from ewes receiving endophyte-infected seed (E + 1.77 mg ergovaline/hd/d) or a control total mixed ration (CON; 0 mg ergovaline/hd/d) tall fescue seed at d-110 and d-133 of gestation was evaluated. Gravid reproduction tracts were collected from ewes. Two-mm sections of umbilical artery and vein were exposed to increasing concentrations of a 5-HT1B/1D agonist and 5-HT2A agonist. The 5-HT1B/1D agonist did not stimulate a contractile response in artery or vein or either gestation time point. 5-HT2A agonist caused large responses in artery with greatest occurring at d-110 and decreasing in magnitude as days of gestation increased (p < 0.05). On d-110 and 133 of gestation, arteries from CON ewes had greater contractile response than arteries collected from E+ ewes (p < 0.05). Veins responded to increasing concentrations of the 5-HT2A agonist. Maximal d-110 vein response was greater than d-133 when exposed to 5-HT2A agonist (p < 0.05). Unlike the artery, veins from E+ ewes had greater d-133 contractile response than CON (p < 0.05). Vascular contractions of umbilical artery and vein are induced by 5-HT2A receptor activity and not 5-HT1B/1D. Umbilical artery 5-HT2A receptor activity was more sensitive to seed treatment and could be responsible for ergot alkaloid-induced intra-uterine growth restriction.

The value of umbilical artery blood gas analysis in the rapid diagnosis of fetomaternal hemorrhage.

As a rare obstetric disease, fetomaternal hemorrhage (FMH) often causes severe fetal anemia, edema and even death, easily to be confused with severe neonatal asphyxia. Currently, there are several ways to detect or predict FMH, however, most of them are flawed and time-consuming, as well as unsuitable for rapid diagnosis and timely intervention of FMH. To explore the values of umbilical artery blood gas analysis in the rapid diagnosis of FMH, providing basis for rapid guidance of newborn rescue. Five cases of neonates with FMH from the First Affiliated Hospital of Army Military Medical University (Chongqing Southwest Hospital) from January 2013 to January 2016 were selected as the study group. Another 9 cases of severe asphyxia neonates were chosen into the control group. The difference in Apgar score and umbilical artery blood gas analysis between the 2 groups at birth was compared, and the treatments and clinical outcomes of the 2 groups were analyzed. The PH value of umbilical artery blood gas analysis in the study group was higher than that of the control group, but the difference was not statistically significant (P > .05). In the study group, cases with pH value < 7.0 accounted for 0%, whereas the cases with pH < 7.0 accounted for 66.67% in the control group, and the difference between the 2 groups was statistically significant (P < .05). Compared with the control group, the arterial oxygen partial pressure (PO2), the absolute value of (PCO2), lactic acid (lac) and alkali were not significantly different from those of the control group (P > .05), while the total hemoglobin (tHb) and hematocrit (Hct) were significantly lower than the control group (P < .0001). In the study group, tHb in the umbilical cord blood of 2 newborns with FMH death was significantly lower than 40 g/L. FMH should be highly suspected when there is an expression of severe asphyxia in neonates, indicated by significantly lower tHb levels in umbilical cord blood. It is helpful to improve the neonatal outcome by FMH neonatal resuscitation as soon as possible.

Fetoplacental unit involvement in uric acid production in women with severe preeclampsia: a prospective case control pilot study.

PURPOSE: Preeclampsia (PE) is a common complication of pregnancy that carries significant risks for both the mother and the fetus, and is frequently accompanied by hyperuricemia, yet the exact source of elevated uric acid (UA) levels remains partially elucidated. Several potential origins for increased UA levels include abnormal renal function, increased tissue breakdown, and increased activity of the enzyme Xanthine Oxidase (XO). The aim of the study was to determine serum levels of UA and XO not only in maternal serum, but also in umbilical vein (UV) and umbilical artery (UA) and explore their possible role in PE development. METHODS: A prospective case-control pilot study was conducted in women who were found positive for PE with severe features, and had elevated UA levels above 6 mg/dL, with normotensive pregnant women serving as controls. Renal function, UA and XO levels were measured in maternal, UV and UA serums immediately after delivery. They were then compared between PE (n = 21) and control (n = 18) groups, as well as across all mediums (maternal, UV and UA) among the total study sample (N = 39). Diastolic blood pressure (DBP) was also measured immediately following delivery. RESULTS: The mean serum maternal creatinine levels did not differ significantly between groups (0.65 ± 0.03 vs 0.6 ± 0.07, p = 0.13). Both mean maternal serum UA and XO concentrations were higher in PE group than in control (7.3 ± 1.2 vs 4.2 ± 0.9, p < 0.01 and 3.6 ± 3.5 Vs 1.7 ± 0.8, p < 0.01, respectively). The mean UV and UA serum XO concentrations were significantly higher in PE group compared to control (4.2 ± 3.6 vs 2.2 ± 1.4, p < 0.01 and 4.2 ± 3.6 vs 2.1 ± 1.5, p < 0.01, respectively). Polynomial fit correlation test demonstrated a significant association between maternal DBP and UV XO concentration for all the total study participants (p = 0.03). CONCLUSION: Despite preserved renal functions, UA and XO levels were elevated in women with PE. Importantly, this pattern was found to be applied to the feto-placental unit as well, which may indicate an active involvement of the fetus in the hypoxic process. Further study is needed to clarify the possible role of the feto-placental unit in pregnancies complicated by PE.

A genetically small fetus impairs placental adaptations near term.

The placenta is a gatekeeper between the mother and fetus, adapting its structure and functions to support optimal fetal growth. Studies exploring adaptations of placentae that support the development of genetically small fetuses are lacking. Here, using a mouse model of impaired fetal growth, achieved by deleting insulin-like growth factor 2 (Igf2) in the epiblast, we assessed placental nutrient transfer and umbilical artery (UA) blood flow during late gestation. At embryonic day (E) 15.5, we observed a decline in the trans-placental flux of glucose and system A amino acids (by using 3H-MeG and 14C-MeAIB), proportionate to the diminished fetal size, whereas UA blood flow was normal. However, at E18.5, the trans-placental flux of both tracers was disproportionately decreased and accompanied by blunted UA blood flow. Feto-placental growth and nutrient transfer were more impaired in female conceptuses. Thus, reducing the fetal genetic demand for growth impairs the adaptations in placental blood flow and nutrient transport that normally support the fast fetal growth during late gestation. These findings have important implications for our understanding of the pathophysiology of pregnancies afflicted by fetal growth restriction.

The role of ultrasound and mitofusin-2 levels to predict pregnancy outcomes in patients with severe preeclampsia: a case-control study.

OBJECTIVE: The aim of this study was to evaluate mitofusin-2 levels and fetal Doppler ultrasonography effects in patients with severe preeclampsia. METHODS: This single-center case-control study was conducted in the gynecology service of the university hospital in Van. A total of 90 pregnant women aged 18-40 years were included in the study. Of these, 30 are normal, 30 have mild preeclampsia, and 30 are pregnant with severe preeclampsia. In this study, especially in severe preeclampsia patients, serum mitofusin-2 levels and important fetal Doppler flows such as uterine arterial pressure, umbilical arterial pressure, and 1st and 5th minute Apgar scores, birth weight, and the relationship between postnatal outcomes such as week of birth and the number of patients in the neonatal intensive care unit were investigated. RESULTS: There was a significant difference between the three groups in terms of mitofusin-2 levels, which was the highest in the group (p<0.05). Maternal serum mitofusin-2 levels were positively correlated with uterine arterial pressure (r=0.543, p=0.007), umbilical arterial pressure (r=0.238, p=0.008), diastolic blood pressure, and systolic blood pressure (p<0.001). Receiver operating characteristic curve of mitofusin-2 in predicting preeclampsia is as follows: optimal cutoff 1.6 ng/mL; area under the curve: 0.861; 95%CI: 0.786-0.917; sensitivity: 83.9%; and specificity: 70.0%, (p≤0.001). A one-unit increase in mitofusin-2 resulted in a statistically significant 4.21-fold increase in preeclampsia risk. CONCLUSION: This study recommends the use of mitofusin-2 together with fetal Doppler ultrasound findings as a reliable indicator of preeclampsia severity.

An investigation of the umbilical artery N-terminal proBrain natriuretic peptide levels of fetuses due to fetal distress in term pregnancies.

OBJECTIVE: This study aimed to investigate umbilical artery N-terminal proBrain natriuretic peptide (NT-proBNP) in fetuses delivered by cesarean section due to fetal distress in term pregnancies. METHODS: This prospective case-control study was conducted at the Antalya Training and Research Hospital Obstetric Department, Turkiye. A total of 140 pregnant women, 70 underwent elective cesarean sections between weeks 37 and 40 of gestation (Group 1, the control group) and 70 underwent cesarean sections due to fetal distress (Group 2, the study group), were included. The participants' sociodemographic and obstetric data and fetal umbilical blood NT-proBNP levels were recorded in a database. RESULTS: Age, body mass index, gestational age, prenatal diagnostic tests, fetal anatomical scanning, and baby gender ratios were comparable between the groups (p>0.05), while statistically significant differences were observed in terms of gravidity (3.0 vs. 1.0, p≤0.001) and parity numbers (2 vs. 0, p≤0.001), baby height (50.36±0.88 vs. 49.80±0.86, p≤0.001) and weight (3422.43±409.16 vs. 3239.86±293.74, p=0.003), 1-min Apgar (9.0±0.1 vs. 8.5±1.3, p≤0.001) and 5-min Apgar (10.0±0.1 vs. 9.8±0.4, p=0.026) scores, umbilical artery pH (7.32±0.05 vs. 7.25±0.07, p≤0.001), umbilical artery base deficit (-2.48±1.23 vs. -4.36±1.09. p≤0.001), and NT-proBNP levels [8.77 (7.72-9.39) vs. 12.35 (9.69-12.92), p<0.001]. CONCLUSION: This study showed that NT-proBNP can be used as an important marker in the diagnosis of fetal distress. Prospective studies with more participants are now needed to confirm the accuracy of our results.

The role of the cerebro-placental-uterine ratio in predicting composite adverse perinatal outcomes in patients with pregnancy-induced hypertension.

OBJECTIVES: To examine the role of the cerebro-placental-uterine ratio (CPUR) in predicting composite adverse perinatal outcomes (CAPO) in patients with pregnancy-induced hypertension (PIH). STUDY DESIGN: This prospective, case-control study was conducted at a tertiary hospital with 110 cases of PIH, including 70 patients with preeclampsia and 40 with gestational hypertension, and 110 healthy controls. The middle cerebral artery pulsatility index (MCA-PI), umbilical artery pulsatility index (UA-PI), and uterine artery pulsatility index (UtA-PI) were measured, and the cerebro-placental ratio (CPR=MCA-PI/UA-PI) and CPUR (CPR/UtA-PI) were calculated. MAIN OUTCOME MEASURE: The role of CPUR in predicting CAPO in preeclampsia and gestational hypertension. RESULTS: The CPR and CPUR values were lower in the PIH group compared to the control group (p < 0.001). CAPO had a negative correlation with CPR and CPUR (p < 0.001). Univariate regression analysis revealed that the likelihood of CAPO was increased four times by a low CPR value and six times by a low CPUR value. In the ROC analysis, the optimal cut-off value of CPR in predicting CAPO was 1.33 with 74 % sensitivity and 66 % specificity (area under the curve [AUC] = 0.778; p < 0.001) in PIH. For CPUR, the optimal cut-off value was 1.32, at which 82 % sensitivity and 79 % specificity in predicting CAPO (AUC=0.826; p < 0.001). CONCLUSION: CPUR was determined to be successful with high sensitivity in predicting adverse perinatal outcomes in the presence of PIH. In addition, CPUR was more effective in predicting CAPO in patients with preeclampsia compared to gestational hypertension. CPUR can be used to predict adverse outcomes in patients with PIH.

Society for Maternal-Fetal Medicine Consult Series #72: Twin-twin transfusion syndrome and twin anemia-polycythemia sequence.

Thirty percent of spontaneously occurring twins are monozygotic, of which two-thirds are monochorionic, possessing a single placenta. A common placental mass with shared intertwin placental circulation is key to the development and management of complications unique to monochorionic gestations. In this Consult, we review general considerations and a contemporary approach to twin-twin transfusion syndrome and twin anemia-polycythemia sequence, providing management recommendations based on the available evidence. The following are the Society for Maternal-Fetal Medicine recommendations: (1) we recommend routine first-trimester sonographic determination of chorionicity and amnionicity (GRADE 1B); (2) we recommend that ultrasound surveillance for twin-twin transfusion syndrome begin at 16 weeks of gestation for all monochorionic-diamniotic twin pregnancies and continue at least every 2 weeks until delivery, with more frequent monitoring indicated with clinical concern (GRADE 1C); (3) we recommend that routine sonographic surveillance for twin-twin transfusion syndrome minimally include assessment of amniotic fluid volumes on both sides of the intertwin membrane and evaluation for the presence or absence of urine-filled fetal bladders, and ideally incorporate Doppler study of the umbilical arteries (GRADE 1C); (4) we recommend fetoscopic laser surgery as the standard treatment for stage II through stage IV twin-twin transfusion syndrome presenting between 16 and 26 weeks of gestation (GRADE 1A); (5) we recommend expectant management with at least weekly fetal surveillance for asymptomatic patients continuing pregnancies complicated by stage I twin-twin transfusion syndrome, and consideration for fetoscopic laser surgery for stage I twin-twin transfusion syndrome presentations between 16 and 26 weeks of gestation complicated by additional factors such as maternal polyhydramnios-associated symptomatology (GRADE 1B); (6) we recommend an individualized approach to laser surgery for early- and late-presenting twin-twin transfusion syndrome (GRADE 1C); (7) we recommend that all patients with twin-twin transfusion syndrome qualifying for laser therapy be referred to a fetal intervention center for further evaluation, consultation, and care (Best Practice); (8) after laser therapy, we suggest weekly surveillance for 6 weeks followed by resumption of every-other-week surveillance thereafter, unless concern exists for post-laser twin-twin transfusion syndrome, post-laser twin anemia-polycythemia sequence, or fetal growth restriction (GRADE 2C); (9) following the resolution of twin-twin transfusion syndrome after fetoscopic laser surgery, and without other indications for earlier delivery, we recommend delivery of dual-surviving monochorionic-diamniotic twins at 34 to 36 weeks of gestation (GRADE 1C); (10) in twin-twin transfusion syndrome pregnancies complicated by posttreatment single fetal demise, we recommend full-term delivery (39 weeks) of the surviving co-twin to avoid complications of prematurity unless indications for earlier delivery exist (GRADE 1C); (11) we recommend that fetoscopic laser surgery not influence the mode of delivery (Best Practice); (12) we recommend that prenatal diagnosis of twin anemia-polycythemia sequence minimally require either middle cerebral artery Doppler peak systolic velocity values >1.5 and <1.0 multiples of the median in donor and recipient twins, respectively, or an intertwin Δ middle cerebral artery peak systolic velocity >0.5 multiples of the median (GRADE 1C); (13) we recommend that providers consider incorporating middle cerebral artery Doppler peak systolic velocity determinations into all monochorionic twin ultrasound surveillance beginning at 16 weeks of gestation (GRADE 1C); and (14) consultation with a specialized fetal care center is recommended when twin anemia-polycythemia sequence progresses to a more advanced disease stage (stage ≥II) before 32 weeks of gestation or when concern arises for coexisting complications such as twin-twin transfusion syndrome (Best Practice).

Ultrasound parameters of arteries and heart in normal fetuses.

BACKGROUND: Currently, no normal ultrasound data of the fetuses during the 20-40 gestation have been obtained for references of fetal growth and development. If such ultrasound data existed for prenatal diagnosis of possible diseases and abnormalities, neonates would be able to get timely treatment immediately after birth. This study was thus performed to obtain ultrasound parameters of normal fetuses during the 20-40 week gestation and the distribution of ultrasound parameters with the gestational age for references of detecting potential fetal diseases and abnormalities. METHODS: Normal fetuses without any abnormalities were enrolled, and the ultrasound parameters of the general biology, arteries, and aorta were measured and analyzed. RESULTS: 417 normal fetuses were enrolled. A significant (P < 0.05) negative correlation with the gestational age was detected in the peak systolic velocity/peak diastolic velocity (S/D), pulsatility index (PI) and resistance index (RI) of the umbilical artery (UA). A relatively stable relationship with the gestational age was detected in the fetal weight%, S/D, PI and RI of the middle cerebral artery (MCA), peak systolic velocity (PSV) and velocity time integral (VTI) of the intra-abdominal UA, fetal heart to chest ratio, mitral valve (MV)- and tricuspid valve (TV)-E/A peak flow velocity, aortic isthmic Z-score and displacement, distance between the brachiocephalic artery-left common carotid artery (BA-LCCA) and LCCA-left subclavian artery (LSA), Z-score of aorta, ascending aorta (AAO), pulmonary artery (PA), main pulmonary artery (MPA), and descending aorta (DAO). A significant (P < 0.05) positive correlation with the gestational age was detected in the fetal biological data, MCA PSV and VTI, free-UA PSV and VTI and cardio-thoracic ratio, cardiac parameters, ductus arteriosus (DA) and isthmus diameter, aortic parameters, PA and MPA diameter, MPA PSV and VTI, isthmus flow volume and velocity and PA flow volume, DA and BA parameters, and LCCA and LSA parameters (flow volume, PSV, and VTI). CONCLUSION: A certain correlation and distribution trend is detected in the ultrasound parameters of normal fetuses, and the ratios among different parameters remain relative stable. These findings can be used for determination of abnormal growth of the fetuses in prenatal ultrasound scan.

Epigenetic regulation by hypoxia, N-acetylcysteine and hydrogen sulphide of the fetal vasculature in growth restricted offspring: A study in humans and chicken embryos.

Fetal growth restriction (FGR) is a common outcome in human suboptimal gestation and is related to prenatal origins of cardiovascular dysfunction in offspring. Despite this, therapy of human translational potential has not been identified. Using human umbilical and placental vessels and the chicken embryo model, we combined cellular, molecular, and functional studies to determine whether N-acetylcysteine (NAC) and hydrogen sulphide (H2S) protect cardiovascular function in growth-restricted unborn offspring. In human umbilical and placental arteries from control or FGR pregnancy and in vessels from near-term chicken embryos incubated under normoxic or hypoxic conditions, we determined the expression of the H2S gene CTH (i.e. cystathionine γ-lyase) (via quantitative PCR), the production of H2S (enzymatic activity), the DNA methylation profile (pyrosequencing) and vasodilator reactivity (wire myography) in the presence and absence of NAC treatment. The data show that FGR and hypoxia increased CTH expression in the embryonic/fetal vasculature in both species. NAC treatment increased aortic CTH expression and H2S production and enhanced third-order femoral artery dilator responses to the H2S donor sodium hydrosulphide in chicken embryos. NAC treatment also restored impaired endothelial relaxation in human third-to-fourth order chorionic arteries from FGR pregnancies and in third-order femoral arteries from hypoxic chicken embryos. This NAC-induced protection against endothelial dysfunction in hypoxic chicken embryos was mediated via nitric oxide independent mechanisms. Both developmental hypoxia and NAC promoted vascular changes in CTH DNA and NOS3 methylation patterns in chicken embryos. Combined, therefore, the data support that the effects of NAC and H2S offer a powerful mechanism of human translational potential against fetal cardiovascular dysfunction in complicated pregnancy. KEY POINTS: Gestation complicated by chronic fetal hypoxia and fetal growth restriction (FGR) increases a prenatal origin of cardiovascular disease in offspring, increasing interest in antenatal therapy to prevent against a fetal origin of cardiovascular dysfunction. We investigated the effects between N-acetylcysteine (NAC) and hydrogen sulphide (H2S) in the vasculature in FGR human pregnancy and in chronically hypoxic chicken embryos. Combining cellular, molecular, epigenetic and functional studies, we show that the vascular expression and synthesis of H2S is enhanced in hypoxic and FGR unborn offspring in both species and this acts to protect their vasculature. Therefore, the NAC/H2S pathway offers a powerful therapeutic mechanism of human translational potential against fetal cardiovascular dysfunction in complicated pregnancy.

Enhancing electrical conductivity and mechanical properties of decellularized umbilical cord arteries using graphene coatings.

Traditional decellularized bioscaffolds possessing intact vascular networks and unique architecture have been extensively studied as conduits for repairing nerve damage. However, they are limited by the absence of electrical conductivity, which is crucial for proper functioning of nervous tissue. This study focuses on investigating decellularized umbilical cord arteries by applying coatings of graphene oxide (GO) and reduced graphene oxide (RGO) to their inner surfaces. This resulted in a homogeneous GO coating that fully covered the internal lumen of the arteries. The results of electrical measurements demonstrated that the conductivity of the scaffolds could be significantly enhanced by incorporating RGO and GO conductive sheets. At a low frequency of 0.1 Hz, the electrical resistance level of the coated scaffolds decreased by 99.8% with RGO and 98.21% with GO, compared with uncoated scaffolds. Additionally, the mechanical properties of the arteries improved by 24.69% with GO and 32.9% with RGO after the decellularization process. The GO and RGO coatings did not compromise the adhesion of endothelial cells and promoted cell growth. The cytotoxicity tests revealed that cell survival rate increased over time with RGO, while it decreased with GO, indicating the time-dependent effect on the cytotoxicity of GO and RGO. Blood compatibility evaluations showed that graphene nanomaterials did not induce hemolysis but exhibited some tendency toward blood coagulation.

Evaluation of fetal cerebral microvascular status and its relationship with fetal growth and development using microvascular imaging technique.

The study conducted retrospective analysis design, aiming to explore the use of Microvascular Imaging Technique (MVFI) to assess fetal cerebral microcirculation and analyze the relationship between Microvascular Index (MVI) and fetal growth and development. 100 pregnant women who met the criteria for fetal growth restriction (FGR) provided in the Expert Consensus on Fetal Growth Restriction (2019 Edition) and underwent routine prenatal examinations at the Obstetrics and Gynecology Department of Peking University Third Hospital from January 2021 to June 2023 were selected as the study subjects. A normal fetus with a fetal weight less than 10 % can be classified as FGR, Pregnant women with fetal umbilical artery (UA) systolic and diastolic (S/D) values ≥3 were included in the observation group, while 200 pregnant women with normal fetuses were selected as the control group during the same period. The fetuses' change in both groups were measured using color Doppler ultrasound, including bi-parietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). The cerebral microcirculation of the fetuses in both groups was evaluated using MVFI, and the MVI values were compared. The clinical characteristics of FGR fetuses with umbilical artery S/D ratio ≥ 3 were summarized, and the correlation between fetal cerebral microvascular status and fetal growth and development was analyzed using Pearson correlation analysis. The outcomes told that the BPD, HC, AC, and FL values of the fetuses in the control group were lower the other's value (P < 0.05), and the MVI and peak systolic velocity of the middle cerebral artery (MCA-PSV) values were also lower in the control group (P < 0.05). Pearson correlation analysis revealed a positive correlation between fetal growth and development and MVI and MCA-PSV values in FGR fetuses. In conclusion, MVFI can monitor and quantitatively analyze fetal intracranial microcirculation, visualize slow blood flow in microvascular structures, and this study provides preliminary evidence of the close relationship between fetal cerebral microcirculation and intrauterine growth and development.

Citral relaxes umbilical vessels of normotensive and preeclamptic parturients.

INTRODUCTION: Citral is a low-toxicity monoterpene that has a vasodilator effect on various smooth muscles, and The present study aimed to evaluate its vasorelaxant effect on umbilical vessels of normotensive parturients (NTP) and with preeclampsia parturients (PEP). METHOD: Segments of human umbilical artery (HUA) and vein (HUV) of NTP or PEP were mounted in a bath to record the force of contraction, under tension of 3.0 gf and contracted with the contracting agents: K+ (60 mM), 5 -HT (10 µM) and Ba2+ (1-30 mM). Next, the effect of citral (1-3000 µM) on these contractions and on basal tone was evaluated. RESULTS: In HUA and HUV, citral (1-1000 µM), in NTP condition, inhibited contractions evoked by K+ (IC50 of 413.5 and 271.3, respectively) and by 5-HT (IC50 of 164.8 and 574.3). In the PEP condition, in HUA and HUV, citral also inhibited the contractions evoked by K+ (IC50 of 363.3 and 218.3, respectively) and 5-HT (IC50 of 432.1 and 520.4). At a concentration of 1000 µM, citral completely or almost completely (>90 %) inhibited all contractions. At a concentration of 100-1000 µM, citral, in general, was already able to reduce the contraction induced by 1-3 mM Ba2+ in both AUH and VUH, under NTP and PEP conditions. DISCUSSION: Citral has been shown to be an effective HUA and HUV vasodilator in NTP and PEP. As its toxicity is low, it suggests that this substance can be considered a potential therapeutic agent.

Fetal sex and the relative reactivity of human umbilical vein and arteries are key determinants in potential beneficial effects of phosphodiesterase inhibitors.

Intrauterine growth restriction (IUGR) is a common complication of pregnancy. We previously demonstrated that IUGR is associated with an impaired nitric oxide (NO)-induced relaxation in the human umbilical vein (HUV) of growth-restricted females compared to appropriate for gestational age (AGA) newborns. We found that phosphodiesterase (PDE) inhibition improved NO-induced relaxation in HUV, suggesting that PDEs could represent promising targets for therapeutic intervention. This study aimed to investigate the effects of PDE inhibition on human umbilical arteries (HUAs) compared to HUV. Umbilical vessels were collected in IUGR and AGA term newborns. NO-induced relaxation was studied using isolated vessel tension experiments in the presence or absence of the nonspecific PDE inhibitor 3-isobutyl-1-methylxanthine (IBMX). PDE1B, PDE1C, PDE3A, PDE4B, and PDE5A were investigated by Western blot. NO-induced vasodilation was similar between IUGR and AGA HUAs. In HUAs precontracted with serotonin, IBMX enhanced NO-induced relaxation only in IUGR females, whereas in HUV IBMX increased NO-induced relaxation in all groups except IUGR males. In umbilical vessels preconstricted with the thromboxane A2 analog U46619, IBMX improved NO-induced relaxation in all groups to a greater extent in HUV than HUAs. However, the PDE protein content was higher in HUAs than HUV in all study groups. Therefore, the effects of PDE inhibition depend on the presence of IUGR, fetal sex, vessel type, and vasoconstrictors implicated. Despite a higher PDE protein content, HUAs are less sensitive to IBMX than HUV, which could lead to adverse effects of PDE inhibition in vivo by impairment of the fetoplacental hemodynamics.NEW & NOTEWORTHY The effects of phosphodiesterase inhibition on the umbilical circulation depend on the presence of intrauterine growth restriction, the fetal sex, vessel type, and vasoconstrictors implicated. The human umbilical vascular tone regulation is complex and depends on the amount and activity of specific proteins but also probably on the subcellular organization mediating protein interactions. Therefore, therapeutic interventions using phosphodiesterase inhibitors to improve the placental-fetal circulation should consider fetal sex and both umbilical vein and artery reactivity.