Frank C L, Storey K B
Department of Ecology and Evolutionary Biology, University of California, Irvine 92717.
J Comp Physiol B. 1995;164(7):536-42. doi: 10.1007/BF00261394.
Golden-mantled ground squirrels (Spermophilus lateralis) are herbivores that hibernate during winter. Although little is known about the nutritional/physiological constraints on hibernation, numerous studies have demonstrated that increasing the amount of linoleic acid (a polyunsaturated fatty acid) in the diet enhances hibernation. This is probably because high linoleic acid diets reduce the melting points of the depot fats produced for hibernation which makes them more metabolizable at low body temperatures. This suggests that a major limitation on hibernation may be obtaining enough linoleic acid in the diet for proper hibernation. In all previous studies, however, the amount of linoleic acid in the diets of free-ranging animals was either not considered, or the range of dietary linoleic acid contents in the experiments was less than that of natural diets. It is thus not known whether the amount of linoleic acid available to hibernators under natural conditions actually limits their torpor patterns. A series of laboratory feeding and hibernation experiments were conducted with S. lateralis and artificial diets with different linoleic acid contents that were either below or above the linoleic acid content of the natural diet. The results demonstrated that when dietary linoleic acid contents are either below or above natural levels, hibernation ability is greatly reduced. Hibernation ability was reduced when the squirrels were maintained on a high linoleic acid diet probably by the production of toxic lipid peroxides in brown adipose tissues. The results indicate that there is an optimal level of dietary linoleic acid for proper hibernation, and this is equal to that of the natural diet.(ABSTRACT TRUNCATED AT 250 WORDS)
金色mantled地松鼠（侧纹黄鼠）是在冬季冬眠的食草动物。尽管对于冬眠的营养/生理限制知之甚少，但大量研究表明，增加饮食中亚油酸（一种多不饱和脂肪酸）的含量可增强冬眠能力。这可能是因为高亚油酸饮食降低了为冬眠而产生的储存脂肪的熔点，这使得它们在低温下更易于代谢。这表明冬眠的一个主要限制可能是在饮食中获取足够的亚油酸以进行适当的冬眠。然而，在所有先前的研究中，要么没有考虑自由放养动物饮食中亚油酸的含量，要么实验中饮食中亚油酸含量的范围小于天然饮食。因此，尚不清楚在自然条件下冬眠动物可获得的亚油酸量是否实际上限制了它们的蛰伏模式。对侧纹黄鼠进行了一系列实验室喂养和冬眠实验，使用了亚油酸含量低于或高于天然饮食亚油酸含量的人工饲料。结果表明，当饮食中亚油酸含量低于或高于自然水平时，冬眠能力会大大降低。当松鼠食用高亚油酸饮食时，冬眠能力降低可能是由于棕色脂肪组织中产生了有毒的脂质过氧化物。结果表明，存在一个适合适当冬眠的饮食亚油酸最佳水平，且这与天然饮食的水平相当。（摘要截短至250字）
