Wang X, Hole D G, Da Costa T H, Evans R D
Nuffield Department of Anaesthetics, Nuffield Department of Clinical Medicine, University of Oxford, Oxfordshire OX2 6HE, United Kingdom.
Am J Physiol. 1998 Aug;275(2):E265-71. doi: 10.1152/ajpendo.1998.275.2.E265.
Metabolism of nonesterified fatty acid (palmitate, 1.1 mM) and triacylglycerol (TAG; triolein, 0.4 mM in the form of both rat chylomicrons and very low density lipoproteins) was studied in isolated perfused working hearts from fed nulliparous, lactating, and weaned rats. Hearts from virgin rats oxidized palmitate readily, but optimal cardiac mechanical performance occurred during perfusion with chylomicrons. In hearts from lactating dams, there was a significant increase in palmitate oxidation and a marked decrease in TAG oxidation from both chylomicrons and very low density lipoproteins compared with hearts from nulliparous animals. There was a concomitant decrease in lipoprotein lipase activity in hearts from lactating animals, and TAG in the absence of palmitate could not support optimal cardiac mechanical function. After litter removal, the changes in fatty acid and TAG metabolism observed in lactation returned to nulliparous values within 96 h. These results suggest that, during lactation, both exogenous and endogenous TAGs are directed away from heart and toward the lactating mammary gland; the heart, therefore, has to rely to a greater extent on nonesterified fatty acid for energy provision under these conditions.
在来自未生育、哺乳和断奶大鼠的离体灌注工作心脏中，研究了非酯化脂肪酸（棕榈酸，1.1 mM）和三酰甘油（TAG；三油精，以大鼠乳糜微粒和极低密度脂蛋白形式存在，0.4 mM）的代谢。未生育大鼠的心脏很容易氧化棕榈酸，但在用乳糜微粒灌注期间心脏机械性能最佳。与未生育动物的心脏相比，哺乳母鼠的心脏中棕榈酸氧化显著增加，而来自乳糜微粒和极低密度脂蛋白的TAG氧化显著减少。哺乳动物心脏中的脂蛋白脂肪酶活性随之降低，并且在没有棕榈酸的情况下，TAG不能支持最佳的心脏机械功能。在去除幼崽后，哺乳期观察到的脂肪酸和TAG代谢变化在96小时内恢复到未生育时的值。这些结果表明，在哺乳期，外源性和内源性TAG都从心脏转向泌乳乳腺；因此，在这些条件下，心脏必须在更大程度上依赖非酯化脂肪酸来提供能量。
