Ontogeny of rat lung type II cells correlated with surfactant lipid and surfactant apoprotein expression.
Ontogeny of rat lung type II cells correlated with surfactant lipid and surfactant apoprotein expression.
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大鼠肺 II 型细胞的个体发育与表面活性剂脂质和表面活性剂脱辅基蛋白表达相关。
DOI：
10.1152/ajplung.1991.260.6.l562
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Young,SL
中科院分区：
文献类型：
--
作者：
Randell,SH;Silbajoris,R;Young,SL
在子宫内生长的最后阶段，肺泡上皮发生显著变化，包括细胞分化和表面活性剂脂质和载脂蛋白的产生增加。我们进行了形态计量学测量的II型细胞的特征，从孕龄20至14天出生后的大鼠。我们还测量了肺组织、支气管肺泡灌洗液和富含板层体部分中的二饱和磷脂酰胆碱（DSPC）和表面活性剂载脂蛋白（SP-A）的量，并估计了SP-A、SP-B和SP-C的肺mRNA含量。灌洗和板层体表面活性剂的脂质和载脂蛋白含量每肺表现出一种模式的急剧上升，在出生后早期，然后大幅下降，第二次增加的第14天。当对肺干重进行标准化时，在出生后第1天在所有隔室中发现最高DSPC值。在板层体或灌洗液中发现的全肺DSPC的分数在出生前后48小时内最大。妊娠第22天，板层体SP-A大于灌洗液SP-A，但一天后灌洗液SP-A是板层体SP-A的16倍。所有三种载脂蛋白mRNA的肺组织含量在出生前急剧增加，在出生后第1周下降，然后再次上升到成人水平。每毫克干肺组织的II型细胞数和板层小体数在出生后第1天最高，在出生后第1周下降了一半。每单位板层体体积的DSPC量在出生后第1天上升到最大值，然后下降超过3倍。这些发现表明，在大鼠出生时，表面活性剂细胞和生化池的扩张模式。
During the last stages of intrauterine growth, remarkable changes occur in the alveolar epithelium that include cellular differentiation and increased production of surfactant lipid and apoprotein. We made morphometric measurements of type II cell characteristics from rats aged gestational day 20 to 14 days postnatal. We also measured the amounts of disaturated phosphatidylcholine (DSPC) and surfactant apoprotein (SP-A) in lung tissue, bronchoalveolar lavage, and a lamellar body-rich fraction, and we estimated the lung content of mRNAs for SP-A, SP-B, and SP-C. Lavage and lamellar body surfactant lipid and apoprotein content per lung showed a pattern of a sharp rise in the early postnatal period, then a substantial decline, and a second increase by day 14. When normalized for dry lung weight, the highest DSPC values were found on postnatal day 1 in all compartments. The fraction of whole lung DSPC found in lamellar body or lavage was greatest in the 48-h period surrounding birth. Lamellar body SP-A was greater than lavage SP-A on gestational day 22, but a day later the lavage SP-A was 16 times greater than the lamellar body SP-A. The lung tissue content of all three apoprotein mRNAs increased sharply before birth, fell during the 1st postnatal wk, and then rose again to adult levels. Type II cell number and lamellar body number per milligram of dry lung tissue was highest on post-natal day 1 and fell by one-half during the 1st postnatal wk. The amount of DSPC per unit of lamellar body volume rose to its greatest value on postnatal day 1 and then decreased more than threefold. These findings indicate a pattern of expansion of surfactant cellular and biochemical pools at the time of birth in the rat.