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Walker D. - One of the best experts on this subject based on the ideXlab platform.

  • Does Maternal-Fetal Transfer of creatine occur in pregnant sheep?
    'American Physiological Society', 2017
    Co-Authors: Baharom S., De Matteo R., Ellery S., Della Gatta P., Bruce C.r., Kowalski G.m., Hale N., Dickinson H., Harding R., Walker D.
    Abstract:

    Our aim was to determine the disposition of creatine in ovine pregnancy and whether creatine is Transferred across the placenta from mother to fetus. Pregnant ewes received either 1) a continuous intravenous infusion of creatine monohydrate or saline from 122 to 131 days gestation, with maternal and fetal arterial blood and amniotic fluid samples collected daily for creatine analysis and fetal tissues collected at necropsy at 133 days for analysis of creatine content, or 2) a single systemic bolus injection of 13Ccreatine monohydrate at 130 days of gestation, with maternal and fetal arterial blood, uterine vein blood, and amniotic fluid samples collected before and for 4 h after injection and analyzed for creatine, creatine isotopic enrichment, and guanidinoacetic acid (GAA; precursor of creatine) concentrations. Presence of the creatine transporter-1 (SLC6A8) and L-arginine:glycine amidinoTransferase (AGAT; the enzyme synthesizing GAA) proteins were determined by Western blots of placental cotyledons. The 10-day creatine infusion increased maternal plasma creatine concentration three- to fourfold (P < 0.05) without significantly changing fetal arterial, amniotic fluid, fetal tissues, or placental creatine content. Maternal arterial 13C enrichment was increased (P < 0.05) after bolus 13Ccreatine injection without change of fetal arterial 13C enrichment. SLC6A8 and AGAT proteins were identified in placental cotyledons, and GAA concentration was significantly higher in uterine vein than maternal artery plasma. Despite the presence of SLC6A8 protein in cotyledons, these results suggest that creatine is not Transferred from mother to fetus in near-term sheep and that the ovine utero-placental unit releases GAA into the maternal circulation. © 2017 the American Physiological Society

  • Does Maternal-Fetal Transfer of creatine occur in pregnant sheep?
    American Physiological Society (United States), 2017
    Co-Authors: Baharom S., De Matteo R., Ellery S., Della Gatta P., Hale N., Dickinson H., Harding R., Bruce C, Kowalski G, Walker D.
    Abstract:

    Our aim was to determine the disposition of creatine in ovine pregnancy and whether creatine is Transferred across the placenta from mother to fetus. Pregnant ewes received either 1) a continuous intravenous infusion of creatine monohydrate or saline from 122 to 131 days gestation, with maternal and fetal arterial blood and amniotic fluid samples collected daily for creatine analysis and fetal tissues collected at necropsy at 133 days for analysis of creatine content, or 2) a single systemic bolus injection of [13C]creatine monohydrate at 130 days of gestation, with maternal and fetal arterial blood, uterine vein blood, and amniotic fluid samples collected before and for 4 h after injection and analyzed for creatine, creatine isotopic enrichment, and guanidinoacetic acid (GAA; precursor of creatine) concentrations. Presence of the creatine transporter-1 (SLC6A8) and L-arginine:glycine amidinoTransferase (AGAT; the enzyme synthesizing GAA) proteins were determined by Western blots of placental cotyledons. The 10-day creatine infusion increased maternal plasma creatine concentration three- to fourfold (P < 0.05) without significantly changing fetal arterial, amniotic fluid, fetal tissues, or placental creatine content. Maternal arterial 13C enrichment was increased (P < 0.05) after bolus [13C]creatine injection without change of fetal arterial 13C enrichment. SLC6A8 and AGAT proteins were identified in placental cotyledons, and GAA concentration was significantly higher in uterine vein than maternal artery plasma. Despite the presence of SLC6A8 protein in cotyledons, these results suggest that creatine is not Transferred from mother to fetus in near-term sheep and that the ovine utero-placental unit releases GAA into the maternal circulation

Baharom S. - One of the best experts on this subject based on the ideXlab platform.

  • Does Maternal-Fetal Transfer of creatine occur in pregnant sheep?
    'American Physiological Society', 2017
    Co-Authors: Baharom S., De Matteo R., Ellery S., Della Gatta P., Bruce C.r., Kowalski G.m., Hale N., Dickinson H., Harding R., Walker D.
    Abstract:

    Our aim was to determine the disposition of creatine in ovine pregnancy and whether creatine is Transferred across the placenta from mother to fetus. Pregnant ewes received either 1) a continuous intravenous infusion of creatine monohydrate or saline from 122 to 131 days gestation, with maternal and fetal arterial blood and amniotic fluid samples collected daily for creatine analysis and fetal tissues collected at necropsy at 133 days for analysis of creatine content, or 2) a single systemic bolus injection of 13Ccreatine monohydrate at 130 days of gestation, with maternal and fetal arterial blood, uterine vein blood, and amniotic fluid samples collected before and for 4 h after injection and analyzed for creatine, creatine isotopic enrichment, and guanidinoacetic acid (GAA; precursor of creatine) concentrations. Presence of the creatine transporter-1 (SLC6A8) and L-arginine:glycine amidinoTransferase (AGAT; the enzyme synthesizing GAA) proteins were determined by Western blots of placental cotyledons. The 10-day creatine infusion increased maternal plasma creatine concentration three- to fourfold (P < 0.05) without significantly changing fetal arterial, amniotic fluid, fetal tissues, or placental creatine content. Maternal arterial 13C enrichment was increased (P < 0.05) after bolus 13Ccreatine injection without change of fetal arterial 13C enrichment. SLC6A8 and AGAT proteins were identified in placental cotyledons, and GAA concentration was significantly higher in uterine vein than maternal artery plasma. Despite the presence of SLC6A8 protein in cotyledons, these results suggest that creatine is not Transferred from mother to fetus in near-term sheep and that the ovine utero-placental unit releases GAA into the maternal circulation. © 2017 the American Physiological Society

  • Does Maternal-Fetal Transfer of creatine occur in pregnant sheep?
    American Physiological Society (United States), 2017
    Co-Authors: Baharom S., De Matteo R., Ellery S., Della Gatta P., Hale N., Dickinson H., Harding R., Bruce C, Kowalski G, Walker D.
    Abstract:

    Our aim was to determine the disposition of creatine in ovine pregnancy and whether creatine is Transferred across the placenta from mother to fetus. Pregnant ewes received either 1) a continuous intravenous infusion of creatine monohydrate or saline from 122 to 131 days gestation, with maternal and fetal arterial blood and amniotic fluid samples collected daily for creatine analysis and fetal tissues collected at necropsy at 133 days for analysis of creatine content, or 2) a single systemic bolus injection of [13C]creatine monohydrate at 130 days of gestation, with maternal and fetal arterial blood, uterine vein blood, and amniotic fluid samples collected before and for 4 h after injection and analyzed for creatine, creatine isotopic enrichment, and guanidinoacetic acid (GAA; precursor of creatine) concentrations. Presence of the creatine transporter-1 (SLC6A8) and L-arginine:glycine amidinoTransferase (AGAT; the enzyme synthesizing GAA) proteins were determined by Western blots of placental cotyledons. The 10-day creatine infusion increased maternal plasma creatine concentration three- to fourfold (P < 0.05) without significantly changing fetal arterial, amniotic fluid, fetal tissues, or placental creatine content. Maternal arterial 13C enrichment was increased (P < 0.05) after bolus [13C]creatine injection without change of fetal arterial 13C enrichment. SLC6A8 and AGAT proteins were identified in placental cotyledons, and GAA concentration was significantly higher in uterine vein than maternal artery plasma. Despite the presence of SLC6A8 protein in cotyledons, these results suggest that creatine is not Transferred from mother to fetus in near-term sheep and that the ovine utero-placental unit releases GAA into the maternal circulation

Judith A Smith - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of the maternal fetal Transfer of granisetron in an ex vivo placenta perfusion model
    Reproductive Toxicology, 2014
    Co-Authors: Justin M Julius, Andrew Tindall, Jerrie S Refuerzo, Pamela D Berens, Kenneth J. Moise, Judith A Smith
    Abstract:

    Abstract The objective of this study was to estimate maternal–fetal transplacental passage of granisetron in an ex vivo placental perfusion model. Term human placentas ( N  = 8) were collected immediately after delivery. A single cotyledon from each placenta was perfused granisetron concentration to mimic systemic maternal peak plasma concentrations following either IV (50 ng/mL) or transdermal administration (5 ng/mL). To assess drug Transfer and accumulation, samples were collected from maternal and fetal compartments. In the 50 ng/mL open model, the mean transport fraction was 0.21 ± 0.08 with clearance index of 0.53 ± 0.66. Fetal peak concentrations achieved was 5.6 ± 6.6 ng/mL with mean accumulation of 5.35 ± 6.4 ng/mL. No drug was detected in the fetal compartment with the 5 ng/mL models. Transplacental passage of granisetron was inconsistent at the 50 ng/mL concentration that achieved with IV dosing. However, there consistently was no detectable passage in all the placentas evaluated of the granisetron at 5 ng/mL concentration that would be achieved after transdermal patch administration.

Laurent Mandelbrot - One of the best experts on this subject based on the ideXlab platform.

  • maternal fetal Transfer and amniotic fluid accumulation of nucleoside analogue reverse transcriptase inhibitors in human immunodeficiency virus infected pregnant women
    Antimicrobial Agents and Chemotherapy, 2004
    Co-Authors: Helene Chappuy, Jeanmarc Treluyer, Vincent Jullien, Jerome Dimet, Elisabeth Rey, Maria Fouche, Ghislaine Firtion, Gerard Pons, Laurent Mandelbrot
    Abstract:

    This study was performed to investigate placental Transfer of nucleoside analogue reverse transcriptase inhibitors (NRTIs) and their concentrations in amniotic fluid when given to human immunodeficiency virus (HIV)-infected pregnant women. A total of 100 HIV type 1-infected mothers receiving antiretroviral therapy, including one or more NRTIs, for clinical indications at the time of delivery were enrolled. Maternal blood samples and amniotic fluid were obtained during delivery or cesarean section, and paired cord blood samples were obtained by venipuncture immediately after delivery. Drug concentrations were measured by using high-performance liquid chromatography. A significant relationship between concentrations in maternal and cord plasma samples was found for zidovudine, lamivudine, stavudine, and didanosine. The ratio between the concentrations in cord and maternal plasma samples (R) was high for zidovudine (R = 1.22), its glucuronide metabolite (3′-azido-3′-deoxythymidine-β-d-glucuronide) (R = 1.01), stavudine (R = 1.32), lamivudine (R = 0.93), and abacavir (R = 1.03) and was low for didanosine (R = 0.38). The ratio between the concentrations in amniotic fluid and cord plasma samples was high for zidovudine (R = 2.24), its glucuronide metabolite (R = 2.83), stavudine (R = 4.87), and lamivudine (R = 3.99) and was lower for didanosine (R = 1.14). These findings indicate that most NRTIs cross the placenta by simple diffusion and are concentrated in the amniotic fluid, probably through fetal urinary excretion. The efficacy or toxicity of NRTIs may vary according to placental Transfer.

De Matteo R. - One of the best experts on this subject based on the ideXlab platform.

  • Does Maternal-Fetal Transfer of creatine occur in pregnant sheep?
    'American Physiological Society', 2017
    Co-Authors: Baharom S., De Matteo R., Ellery S., Della Gatta P., Bruce C.r., Kowalski G.m., Hale N., Dickinson H., Harding R., Walker D.
    Abstract:

    Our aim was to determine the disposition of creatine in ovine pregnancy and whether creatine is Transferred across the placenta from mother to fetus. Pregnant ewes received either 1) a continuous intravenous infusion of creatine monohydrate or saline from 122 to 131 days gestation, with maternal and fetal arterial blood and amniotic fluid samples collected daily for creatine analysis and fetal tissues collected at necropsy at 133 days for analysis of creatine content, or 2) a single systemic bolus injection of 13Ccreatine monohydrate at 130 days of gestation, with maternal and fetal arterial blood, uterine vein blood, and amniotic fluid samples collected before and for 4 h after injection and analyzed for creatine, creatine isotopic enrichment, and guanidinoacetic acid (GAA; precursor of creatine) concentrations. Presence of the creatine transporter-1 (SLC6A8) and L-arginine:glycine amidinoTransferase (AGAT; the enzyme synthesizing GAA) proteins were determined by Western blots of placental cotyledons. The 10-day creatine infusion increased maternal plasma creatine concentration three- to fourfold (P < 0.05) without significantly changing fetal arterial, amniotic fluid, fetal tissues, or placental creatine content. Maternal arterial 13C enrichment was increased (P < 0.05) after bolus 13Ccreatine injection without change of fetal arterial 13C enrichment. SLC6A8 and AGAT proteins were identified in placental cotyledons, and GAA concentration was significantly higher in uterine vein than maternal artery plasma. Despite the presence of SLC6A8 protein in cotyledons, these results suggest that creatine is not Transferred from mother to fetus in near-term sheep and that the ovine utero-placental unit releases GAA into the maternal circulation. © 2017 the American Physiological Society

  • Does Maternal-Fetal Transfer of creatine occur in pregnant sheep?
    American Physiological Society (United States), 2017
    Co-Authors: Baharom S., De Matteo R., Ellery S., Della Gatta P., Hale N., Dickinson H., Harding R., Bruce C, Kowalski G, Walker D.
    Abstract:

    Our aim was to determine the disposition of creatine in ovine pregnancy and whether creatine is Transferred across the placenta from mother to fetus. Pregnant ewes received either 1) a continuous intravenous infusion of creatine monohydrate or saline from 122 to 131 days gestation, with maternal and fetal arterial blood and amniotic fluid samples collected daily for creatine analysis and fetal tissues collected at necropsy at 133 days for analysis of creatine content, or 2) a single systemic bolus injection of [13C]creatine monohydrate at 130 days of gestation, with maternal and fetal arterial blood, uterine vein blood, and amniotic fluid samples collected before and for 4 h after injection and analyzed for creatine, creatine isotopic enrichment, and guanidinoacetic acid (GAA; precursor of creatine) concentrations. Presence of the creatine transporter-1 (SLC6A8) and L-arginine:glycine amidinoTransferase (AGAT; the enzyme synthesizing GAA) proteins were determined by Western blots of placental cotyledons. The 10-day creatine infusion increased maternal plasma creatine concentration three- to fourfold (P < 0.05) without significantly changing fetal arterial, amniotic fluid, fetal tissues, or placental creatine content. Maternal arterial 13C enrichment was increased (P < 0.05) after bolus [13C]creatine injection without change of fetal arterial 13C enrichment. SLC6A8 and AGAT proteins were identified in placental cotyledons, and GAA concentration was significantly higher in uterine vein than maternal artery plasma. Despite the presence of SLC6A8 protein in cotyledons, these results suggest that creatine is not Transferred from mother to fetus in near-term sheep and that the ovine utero-placental unit releases GAA into the maternal circulation