Placental oxygen transfer reduces hypoxia-reoxygenation swings in fetal blood in a sheep model of gestational sleep apnea

Obstructive sleep apnea (OSA), characterized by events of hypoxia-reoxygenation, is highly prevalent in pregnancy, negatively affecting the gestation process and particularly the fetus. Whether the consequences of OSA for the fetus and offspring are mainly caused by systemic alterations in the mother or by a direct effect of intermittent hypoxia in the fetus is unknown. In fact, how apnea-induced hypoxemic swings in OSA are transmitted across the placenta remains to be investigated. The aim of this study was to test the hypothesis, based on a theoretical background on the damping effect of oxygen transfer in the placenta, that oxygen partial pressure (Po2) swings resulting from obstructive apneas mimicking OSA are mitigated in the fetal circulation. To this end, four anesthetized ewes close to term pregnancy were subjected to obstructive apneas consisting of 25-s airway obstructions. Real-time Po2 was measured in the maternal carotid artery and in the umbilical vein with fast-response fiber-optic oxygen sensors. The amplitudes of Po2 swings in the umbilical vein were considerably smaller [3.1 ± 1.0 vs. 21.0 ± 6.1 mmHg (mean ± SE); P < 0.05]. Corresponding estimated swings in fetal and maternal oxyhemoglobin saturation tracked Po2 swings. This study provides novel insights into fetal oxygenation in a model of gestational OSA and highlights the importance of further understanding the impact of sleep-disordered breathing on fetal and offspring development. NEW & NOTEWORTHY This study in an airway obstruction sheep model of gestational sleep apnea provides novel data on how swings in oxygen partial pressure (Po2) translate from maternal to fetal blood. Real-time simultaneous measurement of Po2 in maternal artery and in umbilical vein shows that placenta transfer attenuates the magnitude of oxygenation swings. These data prompt further investigation of the extent to which maternal apneas could induce similar direct oxidative stress in fetal and maternal tissues.

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Placental oxygen transfer reduces hypoxia/reoxygenation swings in fetal blood in a sheep model of gestational sleep apnea

Sleep Medicine ◽

10.1016/j.sleep.2019.11.302 ◽

2019 ◽

Vol 64 ◽

pp. S110

Author(s):

I. Almendros ◽

P. Martinez-Ros ◽

N. Farre ◽

M. Rubio-Zaragoza ◽

M. Torres ◽

...

Keyword(s):

Sleep Apnea ◽

Oxygen Transfer ◽

Fetal Blood ◽

Sheep Model ◽

Hypoxia Reoxygenation

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Late Breaking Abstract - Fetal blood hypoxia/reoxygenation swings are reduced by placental oxygen transfer in a model ovine pregnancy with sleep apnea

10.1183/13993003.congress-2019.oa4929 ◽

2019 ◽

Author(s):

Isaac Almendros ◽

Paula Martínez-Ros ◽

Nuria Farré ◽

Mónica Rubio-Zaragoza ◽

Marta Torres ◽

...

Keyword(s):

Sleep Apnea ◽

Oxygen Transfer ◽

Fetal Blood ◽

Hypoxia Reoxygenation

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Salp metabolism: temperature and oxygen partial pressure effect on the physiology of Salpa fusiformis from the California Current

Journal of Plankton Research ◽

10.1093/plankt/fbz014 ◽

2019 ◽

Vol 41 (3) ◽

pp. 281-291

Author(s):

Lloyd A Trueblood

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Carbon Cycling ◽

Pressure Effect ◽

California Current ◽

Deep Ocean ◽

Hypoxia Tolerance ◽

Metabolic Rates ◽

Physiological Processes ◽

The Impact

Abstract Salps are pelagic tunicates that play an important role in carbon cycling by filter feeding and packaging waste into dense fecal pellets that sink rapidly to the deep ocean. There has been limited research on salp physiology and no studies that examine how changes in environmental factors such as temperature and dissolved oxygen impact basic physiological processes. Here I examine temperature and oxygen partial pressure effect on metabolism in blastozooids of Salpa fusiformis. Routine metabolic rates of 1.66 and 3.95 μmol O2 g−1 h−1 wet weight at 10°C and 17°C, respectively, resulted in a Q10 = 3.45. The observed decrease in metabolism associated with decreased temperature, as well as hypoxia tolerance, is explored in the context of observed vertical migrations into hypoxic waters in the California Current, and potential impacts on carbon output. Metabolic rates for S. fusiformis are compared to metabolic rates published for other species of salps and gelatinous zooplankton. Expansion of this work across a broader set of species is critical to quantify the impact climate change may have on salps and their role in marine carbon cycling.

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Oxygen transfer in foods using oxygen luminescence sensors: Influence of oxygen partial pressure and food nature and composition

Food Chemistry ◽

10.1016/j.foodchem.2010.05.065 ◽

2010 ◽

Vol 123 (4) ◽

pp. 1275-1281 ◽

Cited By ~ 20

Author(s):

C. Pénicaud ◽

S. Guilbert ◽

S. Peyron ◽

N. Gontard ◽

V. Guillard

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Oxygen Transfer ◽

Luminescence Sensors

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Influence of Characteristics of Titanium Oxide Film on the Biological Behavior of Cultured Human Umbilical Vein Endothelial Cells (Huvec)

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.288-289.287 ◽

2005 ◽

Vol 288-289 ◽

pp. 287-290 ◽

Cited By ~ 2

Author(s):

Jun Ying Chen ◽

Yong Xiang Leng ◽

Sh.N. Ge ◽

Ping Yang ◽

Jin Wang ◽

...

Keyword(s):

Endothelial Cells ◽

Oxide Film ◽

Oxygen Partial Pressure ◽

Partial Pressure ◽

Titanium Oxide ◽

Umbilical Vein ◽

Biological Behavior ◽

Titanium Oxide Film ◽

Human Umbilical Vein ◽

X Ray

In the work reported here, titanium oxide film were synthesized using magnetron sputtering from a high-purity Ti metal target while sustaining a differential oxygen partial pressure of from 0.02 to 0.30 Pa. The biological behavior of endothelial cells grown on the film surface was studied by in vitro human umbilical vein endothelial cell (HUVEC) culture investigation. Our studies revealed that the adherence, growth, and proliferation of endothelial cells on different Ti-O film surfaces were strongly affected by the oxygen partial pressure. The biocompatibility mechanisms of ECs on Ti-O film surfaces were explored using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), a-step profilometry, scanning electron microscopy (SEM), and atomic force microscopy (AFM). We conclude that the various film characteristics such as structure, composition and surface morphology due to the different oxygen partial pressures significantly influence the biological behavior of EC.

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