title: Effects of ambient temperature on glucose tolerance and insulin sensitivity test outcomes in normal and obese C57 male mice.
abstract: Mice are commonly used as animal models to study human metabolic diseases, but experiments are typically performed at room temperature, which is far below their thermoneutral zone and is associated with elevated heart rate, food intake, and energy expenditure. We set out to study how ambient temperature affects glucose tolerance and insulin sensitivity in control and obese male mice. Adult male C57BL/6J mice were housed at room temperature (23°C) for 6 weeks and fed either control or high fat diet. They were then fasted for 6 h before glucose or insulin tolerance tests were performed at 15, 20, 25, or 30°C. To ensure that behavioral thermoregulation did not counterbalance the afflicted ambient temperatures, oxygen consumption was determined on mice with the same thermoregulatory opportunities as during the tests. Decreasing ambient temperatures increased oxygen consumption and body mass loss during fasting in both groups. Mice fed high fat diet had improved glucose tolerance at 30°C and increased levels of fasting insulin followed by successive decrease of fasting glucose. However, differences between control and high-fat diet mice were present at all temperatures. Ambient temperature did not affect glucose tolerance in control group and insulin tolerance in either of the groups. Ambient temperature affects glucose metabolism in mice and this effect is phenotype specific.
authors.affiliation: Section for Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark a.dudele@gmail.com.
authors.forename: Anete
authors.initials: A
authors.lastname: Dudele
authors.affiliation: Section for Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
authors.forename: Gitte Marie
authors.initials: GM
authors.lastname: Rasmussen
authors.affiliation: Research and Innovation, VIA University College, Aarhus, Denmark.
authors.forename: David
authors.initials: D
authors.lastname: Mayntz
authors.affiliation: Section for Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Malte
authors.affiliation: Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Sten
authors.initials: S
authors.lastname: Lund
authors.affiliation: Section for Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
authors.forename: Tobias
authors.initials: T
authors.lastname: Wang
keywords: Ambient temperature; C57 mice; glucose tolerance test