Abstract

SCHOSINSKY, Karl; JIMENEZ, Manuel  and  OLIVIA DIMAS, Carmen. Determinación enzimática de fosfolípidos que contienen colina en líquido amniótico. Rev. costarric. cienc. méd [online]. 1998, vol.19, n.1-2, pp.71-85. ISSN 0253-2948.

We describe a method for determining choline containing phospholipids in amniotic fluid. Phospholipase D is used to liberate choline from phospholipids, and the liberated choline is oxidized to betaine and hydrogen peroxide by choline oxidase. The hydrogen peroxide forms a colored complex with phenol and 4-aminoantipyrene in the presence of horseradish peroxidase, and the color is measured spectrophotometrically at 500 nm. The method is linear up to 25 mg/dL. Comparison of the assay (y) with an enzymatic method (x) demostrated a correlation coefficient of 0,945 (regression equation: y = 2,595 + 0,929x). The CV of the between run precision is 2,6 and 4,5 per cent for concentrations of 12,4 and 4,3 mg of phospholipids per 100 mL of amniotic fluid, respectively. The method is relatively simple, precise, and accurate, requires less time and sample that other methods for assessing fetal lung maturity. The procedure is affected by blood, ascorbic acid and bilirrubin.

Keywords : fosfolípidos; líquido amniótico; madurez pulmonar fetal; síndrome de insuficiencia respiratoria; espectrofotometría.