Developmental Study of a Lamellar Body Fraction Isolated From Human Amniotic Fluid
Developmental Study of a Lamellar Body Fraction Isolated From Human Amniotic Fluid
复制标题
从人羊水中分离出的板层体部分的发育研究
作者：
M. Oulton;T. R. Martin;G. Faulkner;D. Stinson;J. P. Johnson
总结：研究了在10，000 x g下将羊水浸泡20 min获得的沉淀级分的几种性质。从这些分析中，我们定义了一个发展概况，似乎描述了胎儿肺表面活性物质系统的成熟过程。在妊娠14至18周，颗粒级分由膜结合囊泡没有内部lamellae。磷脂组成不类似于表面活性剂，主要磷脂是鞘磷脂。这个阶段，指定为presurfactant，持续到30至32周妊娠。此后，在整个发育过程中，颗粒级分的磷脂浓度不断增加，并观察到磷脂组成的逐渐但连续的变化。卵磷脂和磷脂酰肌醇增加39和35周妊娠。在这个阶段中断妊娠，称为表面活性物质合成的开始，导致呼吸窘迫综合征的发病率为100%。从妊娠36周到足月，颗粒部分包含具有层状包涵体特征性形态的结构。在这些制剂中存在的单一膜组分没有贡献的磷脂组合物。早期形成的板层体缺乏磷脂酰甘油，磷脂酰肌醇含量高。一旦磷脂酰甘油出现在板层体组分中，它继续增加，伴随着磷脂酰肌醇的减少，卵磷脂的变化很小。大于1%的总磷脂的磷脂酰甘油值出现代表的成熟阶段，在那里没有呼吸窘迫syndrome.Speculation的风险：从人羊水中获得的颗粒级分的表征导致描述的发展概况，这似乎定义的生化成熟的胎儿肺表面活性物质系统的各个阶段。呼吸窘迫综合征的发展似乎在很大程度上取决于该过程中断的阶段。预计这种分析可用于提供一种简单而特异的胎儿肺成熟度指标。
Summary: Several properties of a pellet fraction obtained on centrifuging amniotic fluid at 10,000 x g for 20 min were investigated. From these analyses, we defined a developmental profile which appears to describe the maturational process of the fetal lung surfactant system. At 14 to 18 wk gestation, the pellet fraction consisted of membrane-bound vesicles without internal lamellae. The phospholipid composition did not resemble that of surfactant, the major phospholipid being sphingomyelin. This stage, designated as presurfactant, persisted until 30 to 32 wk gestation. After this time, the phospholipid concentration of the pellet fraction increased continuously throughout development, and gradual but continuous changes in phospholipid composition were observed. Lecithin and phosphatidylinositol increased between 39 and 35 wk gestation. Interruption of pregnancies at this stage, termed onset of surfactant synthesis, resulted in 100% incidence of respiratory distress syndrome. From 36 wk gestation to postterm, the pellet fraction contained structures with the characteristic morphology of the lamellar inclusion bodies. The presence of single membrane components in these preparations did not contribute to the phospholipid composition. Early formed lamellar bodies lacked phosphatidylglycerol and had a high content of phosphatidylinositol. Once phosphatidylglycerol appeared in the lamellar body fraction, it continued to increase, accompanied by a decrease in phosphatidylinositol with little change in lecithin. A phosphatidylglycerol value of greater than 1% of the total phospholipids appeared to represent the stage of maturity at which there was no risk of respiratory distress syndrome.Speculation: The characterization of a pellet fraction obtained from human amniotic fluid led to the description of a developmental profile which appears to define the individual stages involved in the biochemical maturation of the fetal lung surfactant system. The development of respiratory distress syndrome appears to be very much dependent on the stage at which this process is interrupted. It is expected that such analyses can be adapted to provide a simple, yet specific index of fetal pulmonary maturity.