Phosphatidylcholine inhibits and lysophosphatidylcholine enhances the lymphatic absorption of α-tocopherol in adult rats
Phosphatidylcholine inhibits and lysophosphatidylcholine enhances the lymphatic absorption of α-tocopherol in adult rats
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DOI：
10.1093/jn/131.3.717
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发表时间：
2001-03-01
影响因子：
4.2
通讯作者：
Noh, SK
中科院分区：
文献类型：
--
作者：
Koo, SI;Noh, SK
本研究比较了肠内输注磷脂酰胆碱（PC）和溶血磷脂酰胆碱（lysoPC）对雄性大鼠淋巴吸收α -生育酚（α - TP）的影响。实验中，以3.0 mL/h的速度，将含有5.0 μ mol α - TP、565 μ mol c -14-三油酸（C-14-OA）和396 μ mol Na+-牛磺胆酸的脂质乳液与80 μ mol 1,2-双棕榈酰PC （DPPC）或1,2-二烯油酸PC （DLPC）或不含PC （NoPC）的脂质乳液灌注于24 mt磷酸盐缓冲盐水（pH 6.6）中，持续8 h。在实验2中，比较了1,2-二油基PC （DOPC）和1-油基-2-羟基PC （lysoPC）对大鼠淋巴管中α - TP和c -14-胆固醇吸收的影响，当输注DPPC或DLPC时，α - TP的淋巴吸收明显降低。DPPC和DLPC灌胃大鼠α - TP的累积吸收率分别为对照组（NoPC）的45%和52%。PC组间无显著差异。与NoPC组相比，DPPC或DLPC组大鼠对C-14-OA的吸收增加了42 ~ 43%。DPPC组（34.0 +/- 5.5 mu mol/8 h）和DLPC组（32.4 +/- 2.4 mu mol/8 h）的磷脂输出量也显著高于NoPC组（21.2 +/- 4.2 mu mol/8 h）。与DOPC组相比，lysoPC组α - TP和14c -胆固醇的吸收量显著增加，但两组间PL输出量无显著差异。这些观察结果提供了明确的证据，表明PC存在于脂质乳液中抑制aTP的吸收，而它增强了脂肪的吸收。数据还表明，lysoPC同时增加α - TP和胆固醇的吸收。研究结果表明，肠道PC抑制α - TP的吸收，PC的水解对改善肠道对维生素的吸收至关重要。
This study was conducted to compare the effects of enterally infused phosphatidylcholine (PC) and lysophosphatidylcholine (lysoPC) on the lymphatic absorption of alpha -tocopherol (alpha TP) in male rats. In expt, 1, bile-diverted rats with mesenteric lymph cannulas were infused at 3.0 mL/h for 8 h with a lipid emulsion containing 5.0 mu mol alpha TP, 565 mu mol C-14-triolein (C-14-OA) and 396 mu mol Na+-taurocholate with 80 mu mol 1,2-dipalmitoyl PC (DPPC) or 1,2-dilinoleoyl PC (DLPC) or without PC (NoPC) in 24 mt phosphate-buffered saline (pH 6.6). In expt. 2, the effects of 1,2-dioleoyl PC (DOPC) and 1-oleoyl-2-hydroxy-PC (lysoPC) on alpha TP and C-14-cholesterol absorption were compared in rats with lymph cannulas, When DPPC or DLPC was infused, the lymphatic absorption of alpha TP was lowered drastically. The cumulative absorptions of alpha TP in rats infused with DPPC and DLPC were 45 and 52%, respectively, of the control values (NoPC). No significant difference was noted between the PC groups. In contrast, the absorption of C-14-OA was increased by 42 to 43% in rats infused with DPPC or DLPC compared with that in NoPC rats. Phospholipid outputs also were significantly higher in DPPC (34.0 +/- 5.5 mu mol/8 h) and DLPC (32.4 +/- 2.4 mu mol/8 h) rats than in NoPC rats (21.2 +/- 4.2 mu mol/8 h), When lysoPC was infused, the absorptions of alpha TP and 14C-cholesterol were increased markedly compared with those for DOPC, with no significant difference in PL output between groups infused with DOPC and lysoPC. These observations provide clear evidence that PC present in a lipid emulsion inhibits aTP absorption, whereas it enhances the absorption of fat. The data also demonstrate that lysoPC simultaneously increases the absorption of alpha TP and cholesterol. The findings indicate that luminal PC inhibits the absorption of alpha TP and that hydrolysis of PC is critical to improving the intestinal absorption of the vitamin.