title: A method for preparing radiolabelled rat pulmonary surfactant.
abstract: A method is described for the preparation of rat pulmonary surfactant, radiolabelled specifically in the phosphatidylcholine species, which may be used for degradative studies of the lipoprotein complex. Intravenously administered [methyl-14C]choline chloride is maximally incorporated into alveolar surface surfactant 8 h after injection, and more than 97% of this radiolabel is present in the phosphatidylcholine fraction of the surfactant and, of this, 75% is associated with the dipalmitoyl phosphatidylcholine species. Electron microscopy indicates that the isolated surfactant has a similar physical form to that found at the alveolar surface. The mineral alpha-quartz can be used to increase the yield of surfactant lavaged from the lung surface, but the complex isolated from rats treated in this manner has a low specific radioactivity (less than 1000 d.p.m./mg) compared with that prepared from control animals (22860 d.p.m./mg).
mesh_terms: D000818:Animals; D002250:Carbon Radioisotopes; D002794:Choline / Q000031:analogs & derivatives; D007553:Isotope Labeling / Q000379:methods*; D008297:Male; D010743:Phospholipids / Q000032:analysis; D011663:Pulmonary Surfactants / Q000302:isolation & purification*; D011791:Quartz / Q000494:pharmacology; D051381:Rats; D007507:Therapeutic Irrigation
chemical_list: D002250:Carbon Radioisotopes; D010743:Phospholipids; D011663:Pulmonary Surfactants; C017506:methylcholine; D011791:Quartz; D002794:Choline