You are here

Article Text

Article menu

Download PDFPDF

Cerebral Oxygenation
O-028 Microvascular Tone In The Preterm Neonate: Gasotransmitter Interactions May Be The Key
Free
  1. R Dyson1,
  2. H Palliser2,
  3. J Latter3,
  4. G Chwatko4,
  5. R Glowacki4,
  6. I Wright5
  1. 1Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, Australia
  2. 2Mother and Babies Research Centre HMRI, University of Newcastle, Newcastle, Australia
  3. 3Hunter Medical Research Institute, University of Newcastle, Newcastle, Australia
  4. 4Environmental Chemistry, University of Lodz, Lodz, Poland
  5. 5School of Medicine, University of Wollongong, Wollongong, Australia

Abstract

Background and aims Hydrogen sulphide (H2S) can be produced by one of two enzymes: CSE or CBS. H2S is associated with transitional microvascular tone dysregulation in the preterm infant. We have animal model evidence that increases in H2S associated with microvascular dysregulation are driven by CSE-dependent mechanisms. Nitric oxide (NO) and carbon monoxide (CO) also play a role in the transitional circulation of preterm neonates. The aim of this study was to characterise the interrelationships of all 3 gasotransmitters using structural equation modelling analysis.

Methods 90 preterm neonates were studied at 24h postnatal age. Microvascular studies were performed by laser Doppler. Arterial COHb levels (a measure of CO) were determined through co-oximetry. NO was measured as total nitrate and nitrite in urine. H2S was measured as urinary thiosulphate by liquid chromatography.

Results We observed a positive relationship between NO and H2S (p = 0.008, r = 0.28) and an inverse relationship between CO and H2S (p = 0.01, r = –0.33). No relationship was observed between NO and CO (p = 0.18, r = 0.18). Structural equation modelling was used to examine the combination of these effects on microvascular blood flow. The model with the best fit (χ2 = 1.11) is presented.

Abstract O-028 Figure 1
Abstract O-028 Figure 1

Conclusions NO production positively related to H2S production. Previous studies report that NO inhibits H2S production via the enzyme CBS but induces CSE expression. These results suggest that in the preterm newborn, CSE expression is significantly modulated by NO. The relationship between NO and CSE/H2S may thus be critical to the deleterious higher microvascular blood flow.

https://doi.org/10.1136/archdischild-2014-307384.97

Statistics from Altmetric.com

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.