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Surfactant protein B amount and kinetics in newborn infants: an optimized procedure
Author(s) -
Simonato Manuela,
Baritussio Aldo,
Vedovelli Luca,
Lamonica Giulia,
Carnielli Virgilio Paolo,
Cogo Paola Elisa
Publication year - 2012
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.3065
Subject(s) - chemistry , pulmonary surfactant , kinetics , leucine , derivatization , chromatography , yield (engineering) , extraction (chemistry) , respiratory distress , mass spectrometry , biochemistry , amino acid , surgery , medicine , physics , materials science , quantum mechanics , metallurgy
Surfactant protein B (SP‐B) plays a key role in surfactant homeostasis affecting its biophysical properties and physiological function. Recently, a method to measure SP‐B amount and kinetics from tracheal aspirates (TAs) became available. The main objective of this study was to improve the critical steps of the procedure to obtain a better SP‐B sensitivity. We administered a 24 h continuous infusion of 1 mg/kg/h of 1 13 C‐leucine to ten newborn infants. SP‐B was isolated from serial TAs and its fractional synthesis rate, secretion time, peak time and half life were derived from 13 C enrichment curves obtained by gas chromatography mass spectrometry. SP‐B amount in TAs was also assessed. During the extraction step, acidification and organic solvent ratio optimization doubled the recovery of SP‐B from TAs, so did the elongation of the propylation time (from 20 min to 1 h) with enhanced leucine derivatization yield. Measurement of 13 C leucine enrichments, and therefore all SP‐B kinetics parameters, were successfully calculated in all TAs samples due to the increase of SP‐B yield. SP‐B amount was 0.29 (0.16–0.41) % of total phospholipids with a minimum value of 0.08% belonging to one of the respiratory distress syndrome (RDS) patients. In conclusion, this new procedure enables accurate determination of SP‐B kinetics even in the presence of low protein amount like in preterm RDS patients. Copyright © 2012 John Wiley & Sons, Ltd.