A method of measuring dipalmitoylphosphatidylcholine (DPPC) by high-performance liquid chromatography (HPLC): effect of dexamethasone on DPPC secretion in fetal rat alveolar type II cell culture.

Abstract

To establish a method by which to measure dipalmitoylphosphatidylcholine (DPPC), which is the most prevalent phospholipid in lung surfactant, by high-performance liquid chromatography (HPLC), and to measure DPPC secretion in type-II alveolar cell culture to determine whether glucocorticoid has a direct accerelating effect. Type-II alveolar cell suspensions were made with fetal rat lungs and then cultured. Dexamethasone, (10(-9), 10(-8) M) was added to some of the culture dishes. DPPC was extracted from the culture medium, purified, and measured by high-performance liquid chromatography (HPLC). In the measurements of DPPC, the specificity of isolation and measurement parity were excellent [coefficient of variation: intraassay; 5.66% (0.005 mg/ml), 25.37% (0.05 mg/ml): interassay; 8.35% (0.005 mg/ml), 0.08% (0.05 mg/ml)]. The DPPC concentration in the culture dishes of the dexamethasone was not significantly different than that of the control dishes (Student's t-test). The above results prove that dexamethasone does not directly stimulate lung alveolar type-II cells.