PHOSPHOLIPIDS

phospholipid (conjugated lipid)

• most abundant lipid derived from phosphatidic acid

• originates in the liver and intestine

• produced from the conjugation of two fatty acids and phosphorylated glycerol

neonatal respiratory distress syndrome

• deficiency of the surfactant

head

• hydrophilic (water-loving)

tail

• hydrophobic (water-fearing)

lecithin/phosphatidyl choline

• 70%

spingomyelin

• 20%

• not derived from glycerol but from sphingosine

• lipid disorder - Niemann’s Pick disease

• abnormal amounts of lipids build up in brain, spleen, liver, lungs, and bone marrow

cephalin

• 10%

• phosphatidyl ethanolamine

• phosphatidyl serine

• lysolecithin + inositol phosphatide

estimation of serum lipid phosphorus

• each mole of phosphorus contributes about 4% to the total phospholipid mass; thus phospholipid mass can be determined by multiplying the phospholipid phosphorus conc. (expressed in mg/dL) by 25

lecithin/spingomyelin ratio

• status of fetal lung maturity

• the status of fetal lung maturation is estimated from the evaluation of pulmonary surfactant in amniotic fluid