Bourre J M, Dumont O L, Clément M E, Durand G A
INSERM U 26, Hôpital Fernand Widal, Paris, France.
J Nutr. 1997 Mar;127(3):488-93. doi: 10.1093/jn/127.3.488.
It is important to know whether an organism is able to synthesize all the oleic acid it needs. To determine this, it is sufficient to feed animals a diet containing essential fatty acids but totally lacking oleic acid, and then determine whether tissue concentrations of fatty acids of the (n-9) series are altered due to insufficient endogenous synthesis of oleic acid from stearic acid. In fact, the effects of a total oleic acid deficiency have not previously been studied because all the vegetable oils used in human and animal nutrition contain this fatty acid in variable amounts. Thus, we fed rats semipurified diets whose lipids (triglycerides) were synthesized chemically. Female rats were fed the diets for 3 wk before mating, and their pups (fed the same diets) were killed when 21 and 60 d old. Generally speaking, oleic acid deficiency resulted in a lower level of this acid in the various organs examined (liver, kidney, testes, heart, muscle and sciatic nerve in 21-d-old rats and liver, kidney, heart, muscle and sciatic nerve in 60-d-old rats). Brain, myelin and nerve endings were not affected at either age. This lower level was accompanied by a higher level of 16:1(n-7) and, to a lesser extent, 18:1(n-7). Dietary supplementation with oleic acid (1666 mg/100 g diet) for up to 21 d resulted in normal levels of this fatty acid in some organs (liver, heart, sciatic nerve) but not in others (kidney, muscle, testes) and a decrease in 16:1(n-7), which returned to about the same levels as in the control group in all organs except liver. Adding small or large amounts of stearic acid to the oleic acid-deficient diet had little or no effect on oleic acid levels in the tissues. We conclude that rats (particularly in liver) do not have sufficient synthesizing potential to guarantee the normal fatty acid composition of certain organs if oleic acid is totally absent in the diet.
了解一种生物体是否能够合成其所需的所有油酸非常重要。为了确定这一点，给动物喂食一种含有必需脂肪酸但完全缺乏油酸的饮食，然后确定(n-9)系列脂肪酸的组织浓度是否因从硬脂酸内源性合成油酸不足而发生改变，这就足够了。事实上，此前尚未研究过完全缺乏油酸的影响，因为人类和动物营养中使用的所有植物油都含有不同量的这种脂肪酸。因此，我们给大鼠喂食化学合成脂质（甘油三酯）的半纯化饮食。雌性大鼠在交配前喂食该饮食3周，它们的幼崽（喂食相同饮食）在21日龄和60日龄时被处死。一般来说，油酸缺乏导致在所检查的各个器官（21日龄大鼠的肝脏、肾脏、睾丸、心脏、肌肉和坐骨神经以及60日龄大鼠的肝脏、肾脏、心脏、肌肉和坐骨神经）中该酸的水平较低。在两个年龄段，大脑、髓磷脂和神经末梢均未受到影响。这种较低水平伴随着16:1(n-7)水平的升高，在较小程度上还有18:1(n-7)水平的升高。用油酸（1666毫克/100克饮食）进行长达21天的饮食补充，导致某些器官（肝脏、心脏、坐骨神经）中这种脂肪酸的水平正常，但其他器官（肾脏、肌肉、睾丸）则不然，并且16:1(n-7)有所下降，除肝脏外，所有器官中的该水平都恢复到与对照组大致相同的水平。向缺乏油酸的饮食中添加少量或大量硬脂酸对组织中的油酸水平几乎没有影响。我们得出结论，如果饮食中完全没有油酸，大鼠（尤其是在肝脏中）没有足够的合成潜力来保证某些器官的正常脂肪酸组成。
