Ikegami M, Jobe A H
Division of Pulmonary Biology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA.
Biochim Biophys Acta. 1998 Nov 19;1408(2-3):218-25. doi: 10.1016/s0925-4439(98)00069-6.
The surfactant components saturated phosphatidylcholine, SP-B and SP-C, are secreted together in lamellar bodies, and at least a part of the de novo synthesized SP-A is secreted independently. The surface film forms from tubular myelin and loose lipid arrays, and it generates unilamellar vesicles that lack surfactant proteins and are thought to represent catabolic forms. The half-life values for the clearance of surfactant proteins from lungs range from 6.5 to 28 h and vary with species. There is minimal information about the associations of the surfactant proteins with lipids or with each other after film formation, although all surfactant components seem to be recycled back into lamellar bodies in type II cells. The relative importance of type II cells or macrophages to the catabolism of the protein components of surfactant remains to be characterized, as do regulators of surfactant homeostasis.
表面活性剂成分饱和磷脂酰胆碱、表面活性蛋白B和表面活性蛋白C在板层小体中一起分泌，而新合成的表面活性蛋白A至少有一部分是独立分泌的。表面膜由管状髓鞘和疏松脂质阵列形成，并产生缺乏表面活性剂蛋白的单层囊泡，这些囊泡被认为代表分解代谢形式。表面活性剂蛋白从肺中清除的半衰期值在6.5至28小时之间，且因物种而异。关于表面活性剂蛋白在膜形成后与脂质或彼此之间的关联信息极少，尽管所有表面活性剂成分似乎都在II型细胞中循环回板层小体。II型细胞或巨噬细胞对表面活性剂蛋白成分分解代谢的相对重要性以及表面活性剂稳态的调节因子仍有待确定。
