The mexican free-tailed bat, tadarida brasiliensis, has elevated plasma cholesterol, but very low triglycerides and plaque-free coronary arteries. Widmaier, E. P., E. R. Gornstein, J. L. Hennessey, J. M. Bloss, J. A. Greenberg, and T. H. Kunz. Department of Biology, 5 Cummington St., Boston University, Boston, MA 02215, Tel: 617-353-5563, Fax: 617-353-6340
APStracts 3:0250R, 1996.
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 (post -prandial cholesterol and triglycerides, 268 + 18 and 122 + 20 mg/dL, respectively). HDL-cholesterol levels were extraordinarily high (124 + 5 mg/dL), and unaffected by feeding. LDL-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. 

Received 22 February 1996; accepted in final form 11 June 1996.
APS Manuscript Number R109-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 4 July 96