Rüdiger Mario, Tölle Angelika, Meier Wolfgang, Rüstow Bernd
Clinic for Neonatology, Charité-Mitte; Schumannstr. 21, 10098 Berlin, Germany.
Am J Physiol Lung Cell Mol Physiol. 2005 Feb;288(2):L379-83. doi: 10.1152/ajplung.00176.2004. Epub 2004 Oct 22.
Pulmonary surfactant biophysical properties are best described by surface tension and surface viscosity. Besides lecithin, surfactant contains a variety of minor lipids, such as plasmalogens, polyunsaturated fatty acid-containing phospholipids (PUFA-PL), and cholesterol. Plasmalogens and cholesterol improve surface properties of lipid mixtures significantly. High PUFA-PL and plasmalogen content in tracheal aspirate of preterm infants reduces the risk of developing chronic lung disease. Different preparations are available for exogenous surfactant substitution; however, little is known about lipid composition and surface viscosity. Thus lipid composition and surface properties (measured by oscillating drop surfactometer) of three commercial surfactant preparations (Alveofact, Curosurf, Survanta) were compared. Lipid composition exhibited strong differences: Survanta had the highest proportion of disaturated PL and total neutral lipids and the lowest proportion of PUFA-PL. Highest plasmalogen and PUFA-PL concentrations were found in Curosurf (3.8 +/- 0.1 vs. 26 +/- 1 mol%) compared with Alveofact (0.9 +/- 0.3 vs. 11 +/- 1) and Survanta (1.5 +/- 0.2 vs. 6 +/- 1). In Survanta samples, viscosity increased >8 x 10(-6) kg/s at surface tension of 30 mN/m. Curosurf showed only slightly increased surface viscosity below surface tensions of 25 mN/m, and viscosity did not reach 5 x 10(-6) kg/s. By adding defined PL to Survanta, we obtained a Curosurf-like lipid mixture (without plasmalogens) that exhibited biophysical properties like Curosurf. Different lipid compositions could explain some of the differences in surface viscosity. Therefore, PL pattern and minor surfactant lipids are important for biophysical activity and should be considered when designing synthetic surfactant preparations.
肺表面活性物质的生物物理特性最好用表面张力和表面粘度来描述。除卵磷脂外，表面活性物质还含有多种微量脂质，如缩醛磷脂、含多不饱和脂肪酸的磷脂（PUFA-PL）和胆固醇。缩醛磷脂和胆固醇可显著改善脂质混合物的表面特性。早产儿气管吸出物中高含量的PUFA-PL和缩醛磷脂可降低患慢性肺病的风险。有多种外源性表面活性物质替代品可供使用；然而，人们对其脂质组成和表面粘度了解甚少。因此，比较了三种市售表面活性物质制剂（肺泡表面活性物质、固尔苏、珂立苏）的脂质组成和表面特性（用振荡滴表面张力仪测量）。脂质组成存在显著差异：珂立苏的二饱和磷脂和总中性脂质比例最高，PUFA-PL比例最低。与肺泡表面活性物质（0.9±0.3对11±1）和珂立苏（1.5±0.2对6±1）相比，固尔苏中缩醛磷脂和PUFA-PL的浓度最高（3.8±0.1对26±1摩尔%）。在固尔苏样品中，当表面张力为30 mN/m时，粘度增加>8×10⁻⁶ kg/s。珂立苏在表面张力低于25 mN/m时表面粘度仅略有增加，且粘度未达到5×10⁻⁶ kg/s。通过向固尔苏中添加特定的磷脂，我们得到了一种类似珂立苏的脂质混合物（不含缩醛磷脂），其表现出与珂立苏相似的生物物理特性。不同的脂质组成可以解释表面粘度的一些差异。因此，磷脂模式和微量表面活性物质脂质对生物物理活性很重要，在设计合成表面活性物质制剂时应予以考虑。
