Characterization of pulmonary surfactant from ox, rabbit, rat and sheep

Abstract

1. Pulmonary surfactants from ox, rabbit, rat and sheep were isolated and analysed. 2. All preparations had a high anenoic phosphatidylcholine content and would produce stable surface tensions of 0.01 Nm-1 or less. 3. Protein content was 8-18% of the dry weights. A number of proteins were observed; their overall composition were high in hydrophobic amino acid residues. 4. Lipid content varied from 79% (ox) to 90% (rabbit) with phosphatidylcholine representing from 58% (sheep) to 83% (rabbit) of the total lipid. The surfactant preparations were rather similar in lipid composition except that sheep surfactant contained about 10% lysophosphatidylcholine. 5. Hexadecanoic acid was the principal fatty acid. It was particularly high in phosphatidylcholine. 6. Phosphatidylglycerol was a minor constituent of all surfactants but phosphatidyldimethylethanolamine was not detected.

Enzymatic Determination of Phosphatidylcholine, Sphingomyelin and Phosphatidylglycerol in Lipid Dispersions, Blood Cell Membranes and Rat Pulmonary Surfactant

“…The accuracy of the phosphatidylglycerol determination could only be assessed by using pulmonary surfactant from rats of different ages, because phosphatidylglycerol contents in blood cells were very low, and by comparing our phosphatidylglycerol values with published data using other methods. The phosphatidylglycerol values (6% of total phospholipids) obtained from adult rats are very similar to those previously published (27)(28)(29).…”

“…In adults, this ratio was lower than previously published (29), possibly due to contamination of the bronchoalveolar lavage fluid by plasma proteins (31,32). Nevertheless, this did not modify the phospholipid profile, as can be deduced from the data shown in table 2, which are very similar to those published previously (27)(28)(29). Accordingly, determination of phospholipid profiles does not seem to require the purification of surfactants from associated proteins, with a consequent saving of analysis time.…”

Inspiré par les lipides (Médaille Chevreul 2014)

“…Nous avons ainsi purifié le tensio-actif pulmonaire d'un certain nombre de mammifères (Harwood, 1975) et, avec les connaissances déjà acquises sur les humains (Clements, 1997), avons pu définir les caractéristiques biochimiques uniques de ce remarquable mélange de lipoprotéines (Fig. 1).…”

The Action of Lung Lysosomal Phospholipases on Dipalmitoyl Phosphatidylcholine and its Significance for the Synthesis of Pulmonary Surfactant

“…Preparations of pulmonary surfactant contain 40 to 60% disaturated phosphatidylcholine (15,22). It is difficult to obtain intracellular surfactant free of contaminating lipids, but it must certainly contain more than 60% disaturated phosphatidylcholine.…”

“…The principal lipid, comprising at least 40% of the total, is 1,2-dipalmitoyl phosphatidylcholine (15,22). Most mammalian phosphatidylcholines have at least one unsaturated fatty acid residue (at position 2), but this major component of surfactant has two saturated acids.…”