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Simultaneous measurement of phosphatidylglycerol and disaturated‐phosphatidylcholine palmitate kinetics from alveolar surfactant. Study in infants with stable isotope tracer, coupled with isotope ratio mass spectrometry
Author(s) -
Vedovelli Luca,
Baritussio Aldo,
Carnielli Virgilio Paolo,
Simonato Manuela,
Giusti Pietro,
Cogo Paola Elisa
Publication year - 2011
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1979
Subject(s) - chemistry , phosphatidylglycerol , pulmonary surfactant , phosphatidylcholine , chromatography , isotope ratio mass spectrometry , phospholipid , respiratory distress , mass spectrometry , medicine , biochemistry , surgery , membrane
Disaturated‐phosphatidylcholine (DSPC) and phosphatidylglycerol (PG) are respectively the first and the third most abundant phospholipid in human alveolar surfactant. Their concentration decreases in airway surfactant of adults and infants with respiratory distress syndrome and cystic fibrosis. In this study, we used mass spectrometry (IRMS) to investigate the turnover of DSPC and PG in tracheal aspirates (TA) obtained from infants with normal or diseased lungs. We studied eight infants requiring mechanical ventilation: two with no lung disease, four with diaphragmatic hernia, one with ATP‐binding cassette sub‐family A member 3 heterozygote mutation and one with sepsis. Patients received deuterated water for 48 h as metabolic precursors of palmitate‐DSPC and palmitate‐PG. Serial TAs were obtained every 6 h for five days or until extubation. DSPC and PG were isolated from TA by column and high‐performance thin layer chromatography. Deuterium enrichments of palmitate‐DSPC and PG residues were measured by IRMS coupled with a gas chromatographer. Median secretion time (ST), peak time (PT) and fractional synthesis rate (FSR) were 3.7 [0.9– 13.4] h, 71.0 [52.2 – 85.2] h and 6.6 [6.3 – 11.1] %/day for DSPC and 19.3 [6.4 – 22.8] h, 49.0 [33.0 – 52.5] h and 5.8 [4.8 – 10.9] %/day for PG. This study shows that it is feasible to use deuterium derived from body water to trace simultaneously airway surfactant DSPC and PG in humans. When compared within the same patient, DSPC and PG had similar fractional synthesis rates, but PG had a shorter PT, suggesting differences in the life cycle of these essential surfactant components. Copyright © 2011 John Wiley & Sons, Ltd.