title: Pressure volume curves of lamb lungs and the lecithin-sphingomyelin ratios of lung fluid.
abstract: Pressure-volume curves were made of lungs from non-distressed, from asphyxiated and from distressed lambs. The curves of the non-distressed animals differed from the curves of the asphyxiated and of the distressed group. Eleven stability indices were calculated and the summation of these in situ surfactant characteristics was used for individual respiratory distress syndrome diagnosis. Low values (less than 2) of lecithin/sphingomyelin (L/S) ratios in lung fluid were found before the 130th day of gestation, but a steep increase of the L/S ratio was present after that period. Postnatal RDS was found in low L/S ratio cases, whereas normal lung stability was noticed in animals with L/S ratios greater than 2. It is concluded that the prenatal L/S ratio in lung fluid of lambs is of predicting value in RDS experiments and fits well with lung stability characteristics.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000378:metabolism*; D008176:Lung Volume Measurements; D010713:Phosphatidylcholines / Q000378:metabolism*; D012119:Respiration; D012127:Respiratory Distress Syndrome, Newborn / Q000378:metabolism / Q000662:veterinary*; D012756:Sheep / Q000502:physiology*; D013109:Sphingomyelins / Q000378:metabolism*
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins