Biomaterial Database

Microviscosity of amniotic fluid phospholipids, and its importance in determining fetal lung maturity. 1979

T A Blumenfeld, and H S Cheskin, and M Shinitzky

Fluorescence polarization measurements of microviscosity (apparent viscosity within the hydrophobic center of lipid bilayers) of amniotic fluid correlate well with lecithin/sphingomyelin ratios determined by thin-layer chromatography. In addition to lecithin, phosphatidylglycerol and phosphatidylinositol are important for determining fetal lung maturity, but the lecithin/sphingomyelin ratio gives no information concerning these other phospholipids. The microviscosity of sphingomyelin significantly exceeded that of lecithin over the temperature range 25--37 degrees C; values for phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine were lower. Phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine, added individually, significantly decreased the microviscosity of dispersions with lecithin/sphingomyelin ratios corresponding either to fetal lung immaturity or maturity. Phosphatidylglycerol caused the greatest decrease in both. Mixtures of the three phospholipids in the proportions found in term amniotic fluid decreased the microviscosity of fluids with either mature or immature lecithin/sphingomyelin ratios by 23--27%. When each was present in the proportion found in tracheal aspirate (twice that of term amniotic fluid), the decreases uere 46--50%. This technique quickly and precisely indicates not only fetal lung maturity but also the presence of important phospholipids other than lecithin and sphingomyelin.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D005260	Female		Females
D005333	Fetus	The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.	Fetal Structures,Fetal Tissue,Fetuses,Mummified Fetus,Retained Fetus,Fetal Structure,Fetal Tissues,Fetus, Mummified,Fetus, Retained,Structure, Fetal,Structures, Fetal,Tissue, Fetal,Tissues, Fetal
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000653	Amniotic Fluid	A clear, yellowish liquid that envelopes the FETUS inside the sac of AMNION. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (AMNIOCENTESIS).	Amniotic Fluid Index,Amniotic Fluid Indices,Amniotic Fluids,Fluid Index, Amniotic,Fluid Indices, Amniotic,Fluid, Amniotic,Fluids, Amniotic,Index, Amniotic Fluid,Indices, Amniotic Fluid
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D014783	Viscosity	The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Viscosities