REGULATION OF LIPOPROTEIN-LIPASE IN DIFFERENT RAT-TISSUES
REGULATION OF LIPOPROTEIN-LIPASE IN DIFFERENT RAT-TISSUES
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DOI：
10.1016/0026-0495(88)90178-3
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发表时间：
1988-06-01
影响因子：
9.8
通讯作者：
MCGARRY, JD
中科院分区：
文献类型：
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作者：
KUWAJIMA, M;FOSTER, DW;MCGARRY, JD
在维持无脂饮食的大鼠中，禁食20小时后，肝脏极低密度脂蛋白（VLDL）的产生仅下降18%（根据给予Triton WR1339后血浆甘油三酯积累率判断）。给喂食的大鼠输注肝素引起血浆中两种不同的脂肪酶活性的快速积累，其数量大致相等：肝素释放脂肪酶（HR-LPL）和肝素释放甘油三酯脂肪酶（HR-TGL）。禁食使前者减少67%，而后者仅减少20%至25%。为了深入了解营养状况对这些酶在器官间分布的影响，我们设计了肝脏和心脏的标准灌注实验，以及附睾、腓肠肌（红色纤维）和腰肌（白色纤维）的微技术灌注实验。加入肝素后，分析各种类脂肪酶的灌注液。目的是有选择性地监测毛细血管结合，生理功能脂肪酶没有显著污染的细胞内酶。HR-TGL仅在肝脏中发现，它代表了主要的脂肪酶活性；禁食对它的影响很小。在附睾，禁食动物的HR-LPL下降了85%，值得注意的是，在重新喂食两小时后，几乎反弹到自由进食值。在心脏和腓肠肌中，HR-LPL的方向变化与附睾的方向变化完全相反。相反，腰肌HR-LPL对禁食无反应。从质量上讲，这些数据与记录的营养诱导的vldl -甘油三酯组织处理的变化保持一致。然而，所观察到的一些变化的范围和速度比迄今所认识到的要明显得多。
In rats maintained on a fat-free diet, hepatic production of very low density lipoprotein (VLDL) fell by only 18% after 20 hours of fasting (as judged by rates of triglyceride accumulation in plasma following administration of Triton WR1339). Infusion of heparin into fed rats caused a rapid accumulation in plasma of two distinct lipase activities in approximately equal amounts: heparin releasable lipase (HR-LPL) and heparin releasable triglyceride lipase (HR-TGL). Fasting reduced the former by 67%, but the latter by only 20 to 25%. To gain insight into the effects of nutritional status on the interorgan distribution of these enzymes, experiments were designed for the perfusion of liver and heart by standard procedures, and of epididymis, gastrocnemius muscle (red fiber), and psoas muscle (white fiber) by micro techniques. After addition of heparin, perfusates were analyzed for each species of lipase. The objective was to selectively monitor the capillary-bound, physiologically functional lipase without significant contamination by intracellular enzyme. HR-TGL was found only in liver, where it represented the major lipase activity; it was only minimally affected by fasting. In epididymis HR-LPL fell by 85% in fasted animals and, remarkably, rebounded almost to ad libitum fed values after only two hours of refeeding. In both heart and gastrocnemius muscle, directional changes in HR-LPL were exactly reciprocal to those seen in epididymis. By contrast, HR-LPL of psoas muscle was unresponsive to to fasting. Qualitatively, the data were in keeping with documented nutritionally-induced shifts in tissue disposal of VLDL-triglycerides. However, the extent and rapidity of some of the changes observed were much more pronounced than had hitherto been recognized.