Microvascular circulatory dysregulation driven in part by cystathionine gamma-lyase: A new paradigm for cardiovascular compromise in the preterm newborn

Authors

Rebecca M. Dyson, University of Otago, Hunter Medical Research Institute, University of Newcastle, University of WollongongFollow
Hannah K. Palliser, Hunter Medical Research Institute, University of Newcastle
Nicole Wilding, University of Wollongong
Megan A. Kelly, University of WollongongFollow
Grazyna Chwatko, University of Lodz
Rafal Glowacki, University of Lodz
Mary J. Berry, University of Otago
Xin Ni, Second Military Medical University
Ian M. R Wright, University of Wollongong, Hunter Medical Research Institute, University of NewcastleFollow

RIS ID

131480

Publication Details

Dyson, R. M., Palliser, H. K., Wilding, N., Kelly, M. A., Chwatko, G., Glowacki, R., Berry, M. J., Ni, X. & Wright, I. M. R. (2019). Microvascular circulatory dysregulation driven in part by cystathionine gamma-lyase: A new paradigm for cardiovascular compromise in the preterm newborn. Microcirculation, 26 (2), e12507-1-e12507-13.

Abstract

Objective: H₂S may explain the dysregulation of microvascular tone associated with poor outcome following preterm birth. In adult vasculature, H₂S is predominantly produced by CSE. We hypothesized that vascular CSE activity contributes to microvascular tone regulation during circulatory transition.

Methods: Preterm (GA62) and full-term (GA69) guinea pig fetuses and neonates were studied. Microvascular blood flow was assessed by laser Doppler flowmetry. Thiosulfate, primary urinary metabolite of H₂S, was determined by high-performance liquid chromatography. Real-time H2S production was assessed using a microrespiration system in fetal and postnatal (10, 24 hours) skin and heart samples. CSE contribution was investigated by inhibition via propargylglycine.

Results: In preterm animals, postnatal H₂S production capacity in peripheral vasculature increased significantly and was significantly reduced by the inhibition of CSE. Urinary thiosulfate correlated with both microvascular blood flow and capacity of the vasculature to produce H₂S. H₂S produced via CSE did not correlate directly with microvascular blood flow.

Conclusions: In preterm neonates, H₂S production increases during fetal-to-neonatal transition and CSE contribution to total H₂S increases postnatally. CSE-dependent mechanisms may therefore underpin the increase in H₂S production over the first 72 hours of life in preterm human neonates, associated with both central and peripheral cardiovascular instability.