Stimulation of secretion of disaturated phosphatidylcholine from isolated alveolar type II cells by 12-O-tetradecanoyl-13-phorbol acetate.
Stimulation of secretion of disaturated phosphatidylcholine from isolated alveolar type II cells by 12-O-tetradecanoyl-13-phorbol acetate.
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12-O-十四烷酰基-13-佛波醇乙酸酯刺激分离的 II 型肺泡细胞分泌二饱和磷脂酰胆碱。
DOI：
10.1164/arrd.1978.118.4.705
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
R. Mason
中科院分区：
文献类型：
--
作者：
L. Dobbs;R. Mason
肺泡II型合成和分泌肺表面活性物质；体内分泌的刺激因素和发生分泌的机制尚不清楚。我们从纯化的II型细胞群体中研究了表面活性物质的主要成分--饱和磷脂酰胆碱的分泌。我们通过胰酶处理、不连续密度梯度离心和原代培养中的贴壁，从成年雄性大鼠的肺中分离出II型细胞，制备的II型细胞占93+/-5%(平均+/-SD；n=10)。基础分泌量占细胞总碳-14[14C]-饱和磷脂酰胆碱的2.9%(n=16)。我们发现，10(-8)M12-O-十四酰-13-佛波酯(TPA)是一种刺激其他细胞系统分泌的物质，它能引起14C-不饱和磷脂酰胆碱的释放，其释放速度是基础速率的8.4倍。与我们测试的任何其他物质相比，TPA引起的饱和磷脂酰胆碱的释放更大。低温(4摄氏度)抑制了85%的基础释放和98%的TPA刺激释放。10(-6)M秋水仙碱和10(-5)M长春花碱分别抑制25%和33%TPA的作用。孵育3小时后，对照组细胞培养液中乳酸脱氢酶含量为6.3+/-1.3%(平均+/-SD；n=5)；TPA处理组细胞培养液中乳酸脱氢酶总量为6.7+/-1.5%(n=5)。我们的结论是，TPA诱导的不饱和卵磷脂的分泌是一个可能由微管介导的活跃过程。因为它对分泌有很大的刺激作用，TPA可能有助于研究表面活性物质的分泌机制。
Alveolar type II synthesize and secrete pulmonary surface-active material; the stimuli for secretion in vivo and the mechanisms by which secretion occurs are not well understood. We studied the secretion of disaturated phosphatidylcholine, the principal component of surfactant, from a purified population of type II cells. We isolated type II type from the lungs of adult male rats by treatment with trypsin, centrifugation over discontinuous density gradients, and adherence in primary culture; our preparations were 93 +/- 5 per cent (mean +/- SD; n = 10) type II cells. Basal secretion was 2.9 +/- 1.0 per cent (n = 16) of total cellular carbon-14 [14C]-disaturated phosphatidycholine in 3 hours. We found that 10(-8) M 12-O-tetradecanoyl-13-phorbol-acetate (TPA), a substance that has been shown to stimulate secretion in other cell systems, caused a release of 14C-disaturated phosphatidylcholine that was 8.4 times the basal rate. TPA caused a greater release of disaturated phosphatidylcholine than did any other substance that we have tested. Low temperature (4 degree C) inhibited the basal release by 85 per cent and the TPA-stimulated release by 98 per cent. The effect of TPA was also inhibited 25 per cent by 10(-6) M colchicine and 33 per cent by 10(-5) M vinblastine. Medium from control cells contained 6.3 +/- 1.3 per cent (mean +/- SD; n = 5) of total cellular lactate dehydrogenase (a marker for cell damage) after a 3-hour incubation period; medium from cells treated with TPA contained a similar amount, 6.7 +/- 1.5 per cent (n = 5). We concluded that the TPA-induced secretion of disaturated phosphatidylcholine is an active process probably mediated by microtubules. Because it has a large stimulatory effect on secretion, TPA may be useful for the study of the mechanisms by which surfactant is secreted.