[Frontiers in Bioscience E2, 59-67, January 1, 2010]

The relation of S100beta and metabolic and endocrine responses to acute fetal hypoxemia

Avnesh S Thakor1, Diego Gazzolo2,3, Rosanna Frulio2, Dino A Giussani1

1Department of Physiology University of Cambridge, Cambridge, UK, 2Department of Pediatrics and Neuroscience, Giannina Gaslini Children's University Hospital, Genoa I-16147, Italy, 3Department of Maternal Fetal and Neonatal Health, G. Garibaldi Hospital Catania, Italy

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Materials and methods
3.1. Surgical preparation
3.2. Experimental protocol
3.2.1. Blood sampling regimen
3.2.2. Hormone analyses
3.2.2.1. S100beta assay
3.2.2.2. ACTH assay
3.2.2.3 ... Cortisol assay
3.2.2.4. NPY assay
3.2.2.5. Catecholamine assay
3.3. Data and statistical analyses
4. Results
4.1. Fetal arterial blood gas and metabolic status
4.2. Fetal endocrine status
4.3. Plasma S100beta during acute hypoxemia
4.4. The relationship between plasma S100beta and stress hormone concentrations
4.5. The relationship between plasma S100beta and blood glucose and lactate concentrations
5. Discussion
6. Acknowledgements
7. References

1. ABSTRACT

Elevations in S100beta protein in umbilical cord blood have been proposed as a reproducible marker of fetal stress, leading to cell damage within the central nervous system. However, it remains unknown whether fetal S100beta concentrations correlate with established endocrine and metabolic indices of fetal distress. Hence, in the late gestation ovine fetus, plasma concentrations of S100beta, adrenocorticotropic hormone (ACTH), cortisol, neuropeptide Y (NPY), and catecholamines and blood concentrations of glucose and lactate were measured during acute hypoxemia. Under general anesthesia, 5 sheep fetuses were chronically instrumented with catheters and subjected 5 days later to 1h normoxia, 0.5h hypoxemia and 1h recovery. Plasma samples were taken during each experimental period. Hypoxemia induced significant falls in PaO2 with increases in fetal plasma concentrations of ACTH, cortisol, catecholamines and NPY, and elevations in blood glucose and lactate, all of which showed significant positive relationships with fetal plasma S100beta concentrations. Hence, evaluation of S100beta may provide a valuable clinical tool in the assessment of fetal well-being in suspected complicated pregnancies.