Widmaier E P, Gornstein E R, Hennessey J L, Bloss J M, Greenberg J A, Kunz T H
Department of Biology, Boston University, Massachusetts 02215, USA.
Am J Physiol. 1996 Nov;271(5 Pt 2):R1101-6. doi: 10.1152/ajpregu.1996.271.5.R1101.
Female mammals typically become hyperphagic from mid- to late pregnancy and during lactation. Mexican free-tailed bats, Tadarida brasiliensis mexicana, double their nightly food intake from late pregnancy to peak lactation and consume an insect diet that is exceptionally high in fat. During late pregnancy and throughout lactation, fasting plasma levels of cholesterol in this insectivorous bat are high (215 +/- 8 mg/dl) and are nearly 10-fold higher than in three species of Old World frugivorous bats. Fasting triglycerides were unexpectedly low in T. brasiliensis (25 +/- 2 mg/dl), despite evidence of high fat intake during nightly feeding bouts (postprandial cholesterol and triglycerides, 268 +/- 18 and 122 +/- 20 mg/dl, respectively). High-density lipoprotein (HDL) cholesterol levels were extraordinarily high (124 +/- 5 mg/dl) and unaffected by feeding. Low-density lipoprotein cholesterol levels were correspondingly low (86 +/- 7 mg/dl). This unusual plasma lipid profile was not associated with coronary or aortic atherosclerosis, nor was there evidence of hyperglycemia or hyperinsulinemia. A high-fat diet and high levels of cholesterol in T. brasiliensis are not correlated with cardiovascular disease or (possibly) insulin resistance. Among several possible factors that might account for these observations, nightly bouts of powered flight (commuting and foraging for food) may contribute to elevated HDL cholesterol, which may protect this species from developing atherosclerosis.
雌性哺乳动物通常在怀孕中期到后期以及哺乳期会变得食欲亢进。墨西哥无尾蝠（Tadarida brasiliensis mexicana）从怀孕后期到泌乳高峰期，夜间食物摄入量会翻倍，并且食用的昆虫饮食脂肪含量异常高。在怀孕后期和整个哺乳期，这种食虫蝙蝠的空腹血浆胆固醇水平很高（215±8毫克/分升），几乎比三种旧大陆食果蝠高出10倍。尽管有证据表明在夜间进食期间高脂肪摄入（餐后胆固醇和甘油三酯分别为268±18和122±20毫克/分升），但巴西无尾蝠的空腹甘油三酯却出乎意料地低（25±2毫克/分升）。高密度脂蛋白（HDL）胆固醇水平极高（124±5毫克/分升）且不受进食影响。低密度脂蛋白胆固醇水平相应较低（86±7毫克/分升）。这种不寻常的血浆脂质谱与冠状动脉或主动脉粥样硬化无关，也没有高血糖或高胰岛素血症的证据。巴西无尾蝠的高脂肪饮食和高胆固醇水平与心血管疾病或（可能）胰岛素抵抗无关。在可能解释这些观察结果的几个因素中，夜间的动力飞行（通勤和觅食）可能有助于提高HDL胆固醇水平，这可能保护该物种不发生动脉粥样硬化。
