Influence of intratracheal application of fluorocarbon 72 and different lipid-mixtures on mechanical behavior of isolated immature pig lungs.
Substitution of surfactant in immature lungs has two functional targets: the reduction of the overall alveolar surface tension and the mechanical stabilization of the system of alveoli having different diameters. Indeed, the lowering of the surface tension facilitates the inflation of the lungs, but according to Laplace's law small and large alveoli are not in pressure equilibrium as long as the surface tension is equal in both small and large alveoli. In the present work, we tried to stabilize the lungs and to compare the effect of bolus surfactant substitution with the two-step substitution of fluorocarbons and surfactant. In all, 24 fetal immature lungs were used. For our experiments we used fluorocarbon 72 (FC-72) with a surface tension of 12 mN/m. In groups 1 and 2, a mixture of dipalmitoylphosphatidylcholine (DPPC): cholesterol 9:1 (molar ratio) or DPPC: phosphatidylglycerol (PG) 9:1 (molar ratio) was administered intratracheally as a bolus. In the case of groups 3 and 4, the immature lungs were rinsed first with FC-72. After removing the fluorocarbon, the lungs were artificially ventilated and the DPPC: cholesterol 9:1 (group 3) or DPPC:PG 9:1 mixture (group 4) was given in aerosol form. Static pressure-volume curves (p-v) of the mean values of the 6 lungs in each group were registered at the beginning (0 min) and after 20 and 40 min of artificial ventilation. Airway opening pressure, weight-specific end-inspiratory lung compliance, and phospholipid contents were investigated.(ABSTRACT TRUNCATED AT 250 WORDS)
Widjaja
B
B
Institute of Pharmacology and Toxicology, Faculty for Clinical Medicine Mannheim, University of Heidelberg, Federal Republic of Germany.
Wuthe
J
J
Zimmermann
U
U
Rüfer
R
R
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002784:Cholesterol / Q000008:administration & dosage / Q000494:pharmacology*; D004347:Drug Interactions; D005466:Fluorocarbons / Q000008:administration & dosage / Q000494:pharmacology*; D005865:Gestational Age; D007267:Injections; D008170:Lung Compliance / Q000187:drug effects*; D009929:Organ Size / Q000187:drug effects; D009993:Osmium Tetroxide; D010715:Phosphatidylglycerols / Q000008:administration & dosage / Q000494:pharmacology*; D011650:Pulmonary Alveoli / Q000187:drug effects* / Q000196:embryology / Q000502:physiology; D011897:Random Allocation; D013047:Specific Pathogen-Free Organisms; D013500:Surface Tension; D013501:Surface-Active Agents / Q000008:administration & dosage / Q000494:pharmacology*; D013552:Swine; D013556:Swine, Miniature / Q000196:embryology / Q000502:physiology; D014132:Trachea
D005466:Fluorocarbons; D010715:Phosphatidylglycerols; D013501:Surface-Active Agents; C072954:fluorocarbon 72; D015060:1,2-Dipalmitoylphosphatidylcholine; D002784:Cholesterol; D009993:Osmium Tetroxide