Tölle Angelika, Meier Wolfgang, Rüdiger Mario, Hofmann Klaus Peter, Rüstow Bernd
Institut für medizinische Physik und Biophysik, Universitätsklinikum Charité, Humboldt Universität, D-10098 Berlin, Germany.
Chem Phys Lipids. 2002 Feb;114(2):159-68. doi: 10.1016/s0009-3084(01)00204-3.
Low viscosity of the surface of alveolar fluid is mandatory for undisturbed surfactant function. Based on the known reduction of the viscosity of surfactant-like phospholipid (PL-) mixtures by plasmalogens, the effect of cholesterol and surfactant protein (SP-) B on surface viscosity of these lipid mixtures has been studied. Surface viscosity at the corresponding surface tension was measured with the oscillating drop surfactometer. We found that the viscosity was lowest in cholesterol-, followed by plasmalogen- and SP-B containing samples. Addition of SP-B to a plasmalogen-containing PL-mixture caused a further decrease in viscosity. However, in cholesterol containing mixtures, addition of SP-B led to a significant increase in viscosity, and the effect was reversed by further addition of plasmalogens. We conclude that SP-B, plasmalogens and cholesterol all affect the surface viscosity, thus synergistically regulate monolayer stability. This suggests that they are all needed in vivo for fine tuning of surface properties of pulmonary surfactant.
肺泡液表面的低粘度对于表面活性剂的正常功能至关重要。基于已知的缩醛磷脂可降低类表面活性剂磷脂（PL-）混合物的粘度，研究了胆固醇和表面活性剂蛋白（SP-）B对这些脂质混合物表面粘度的影响。用振荡滴表面张力仪测量了相应表面张力下的表面粘度。我们发现，含胆固醇的样品粘度最低，其次是含缩醛磷脂和SP-B的样品。向含缩醛磷脂的PL混合物中添加SP-B会导致粘度进一步降低。然而，在含胆固醇的混合物中，添加SP-B会导致粘度显著增加，进一步添加缩醛磷脂可逆转这种效应。我们得出结论，SP-B、缩醛磷脂和胆固醇均会影响表面粘度，从而协同调节单层稳定性。这表明它们在体内对于肺表面活性剂表面性质的精细调节都是必需的。
