We are interested in the molecular and behavioral mechanisms that result in obesity or weight gain in mammals. To study this, we use several models of either adaptive or maladaptive weight gain. For example, pregnant mammals increase adiposity and weight as an adaptive response to the metabolic demands of pregnancy and subsequent lactation. Hibernating mammals also gain weight and adiposity as an adaptive response, in this case to the challenges of long-term fasting during hibernation. We are examining the endocrine, neural, and molecular mechanisms that promote such adaptive weight gain, in order to determine how mammals control their body mass and adiposity. Understanding the mechanisms of adaptive weight gain may provide clues to the causative factors of maladaptive weight gain (obesity). We are examining several models of maladaptive weight gain. In one, mice are fed diets composed of various combinations and amounts of fats (saturated or unsaturated) and carbohydrates.
We have found that mice fed high-fat diets gain weight without increasing energy consumption. The weight gain is associated with changes in hypothalamic expression of genes that mediate the actions of the satiety hormone leptin. We are also examining the effects of high fat diets on intestinal remodeling and gene expression. It is hoped that using an approach that compares and contrasts the molecular mechanisms that result in adaptive vs. maladaptive fattening in mammals, it may be possible to better understand the etiology of obesity.
- Lynes M, Narisawa S, Millán JL, Widmaier EP (2011). Interactions between CD36 and global intestinal alkaline phosphatase in mouse small intestine and effects of high-fat diet. Am J Physiol Regul Integr Comp Physiol. Dec;301(6):R1738-47.
- Lynes MD and Widmaier EP. (2011). Involvement of CD36 and intestinal alkaline phosphatases in fatty acid transport in enterocytes, and the response to a high-fat diet. Life Sciences, 88:384-391.
- Reeder DM and Widmaier EP. (2009). Hormone analysis in bats. In: Kunz TH and Parsons S, eds., Ecologoical and Behavioral Methods for the Study of Bats. 2nd edition, The Johns Hopkins University Press.
- Schulz LC, Widmaier EP, Qui J and Roberts RM. (2009). Effect of leptin on mouse trophoblast giant cells.Biol Reprod 80: 415-424.
- Townsend KL, Lorenzi ML, and Widmaier EP. (2008). High-fat diet-induced changes in body mass and hypothalamic gene expression in wild-type and leptin-deficient mice. Endocrine 33:176-188.
- Townsend KL, Kunz TH and Widmaier EP. (2008). Changes in body mass, plasma leptin, and mRNA levels of leptin receptor isoforms during the premigration/prehibernation period in Myotis lucifugus. J Comp Physiol B, 178(2), 217-23.
- Schulz LC, Townsend K, Kunz TH and Widmaier EP. (2007). Inhibition of trophoblast invasiveness in vitro by immunoneutralization of leptin in the bat, Myotis lucifugus (Chiroptera). Gen Comp Endo 150, 59-65.
- Bruder ED, Lee JJ, Widmaier EP, and Raff H. (2007). Microarray and real-time PCR analysis of adrenal gland gene expression in the 7-day-old rat: effects of hypoxia from birth. Physiol Gen 29, 193-200.
- Brooker R, Widmaier EP, Graham LK, and Stiling P. Biology. (2016). 4th edition. McGraw-Hill Higher Education
- Widmaier EP, Raff H, and Strang K. (2016). Vander’s Human Physiology: The Mechanisms of Body Function, 14th edition, McGraw-Hill Higher Education.
- Widmaier EP: Why Geese Don’t Get Obese (and we do): How Evolution’s Strategies for Survival Affect Our Everyday Lives. Publisher: W H Freeman and Co, NY (1998).
- Widmaier EP: The Stuff of Life: Profiles of the Molecules That Make Us Tick. Publisher: Henry Holt and Co, NY (2002).
- BI 315 Systems Physiology