Compton S K, Hamosh M, Hamosh P
Biochim Biophys Acta. 1984 Aug 15;795(1):30-6. doi: 10.1016/0005-2760(84)90101-2.
We have measured the hydrolysis of tri-, di- and monoacylglycerols and of phosphatidylcholine in the lung and have quantitated the incorporation of glyceride and phospholipid fatty acids into lung lipids. Lipolytic activity was studied in the isolated, ventilated, rat lung perfused for 100 min in a recycling system with Krebs-Ringer bicarbonate buffer containing 3% bovine serum albumin, 5.6 mM glucose, and the lipid emulsions. Triacylglycerols were hydrolyzed at significantly (P less than 0.05) lower rates than partial acylglycerols. Hydrolysis of di- and triacylglycerols was significantly lower in lungs of animals given i.v. heparin 60 min prior to death. The incorporation of fatty acids released from acylglycerols was greater into lung neutral fats than into lung phospholipids. Phosphatidylcholine was also hydrolyzed in the isolated perfused lung. The data show that (a) neutral glycerides and phospholipids are hydrolyzed in the isolated, ventilated, perfused rat lung; (b) the hydrolysis of tri- and diacylglycerols is markedly inhibited in lungs isolated from rats given heparin (100 U/kg) 1 h prior to death, whereas the hydrolysis of monoacylglycerol is unaffected by heparin administration, suggesting that tri- and diacylglycerols are hydrolyzed by endothelial lipoprotein lipase, whereas hydrolysis of monoacylglycerol is catalyzed by a separate monoacylglycerol lipase; (c) free fatty acids released by lipoprotein lipase are used by the lung for metabolic needs.
我们已测定了肺中三酰甘油、二酰甘油、单酰甘油以及磷脂酰胆碱的水解情况，并对甘油酯和磷脂脂肪酸掺入肺脂质的情况进行了定量分析。在一个循环系统中，用含有3%牛血清白蛋白、5.6 mM葡萄糖和脂质乳剂的 Krebs-Ringer 碳酸氢盐缓冲液对分离的、通气的大鼠肺进行灌注100分钟，研究其脂解活性。三酰甘油的水解速率显著（P小于0.05）低于部分酰甘油。在死亡前60分钟静脉注射肝素的动物肺中，二酰甘油和三酰甘油的水解明显降低。从酰甘油释放的脂肪酸掺入肺中性脂肪的量比掺入肺磷脂的量更多。磷脂酰胆碱在分离的灌注肺中也会水解。数据表明：（a）中性甘油酯和磷脂在分离的、通气的、灌注的大鼠肺中会水解；（b）在死亡前1小时给予肝素（100 U/kg）的大鼠分离的肺中，三酰甘油和二酰甘油的水解受到显著抑制，而单酰甘油的水解不受肝素给药的影响，这表明三酰甘油和二酰甘油由内皮脂蛋白脂肪酶水解，而单酰甘油的水解由一种单独的单酰甘油脂肪酶催化；（c）脂蛋白脂肪酶释放的游离脂肪酸被肺用于代谢需求。
