An age-dependent alteration of the respiratory exchange ratio in the db/db mouse.
- Author:
Hye Min CHOI
1
;
Hae Rim KIM
;
Eun Kyoung KIM
;
Yong Sub BYUN
;
Young Suk WON
;
Won Ki YOON
;
Hyoung Chin KIM
;
Jong Goo KANG
;
Ki Hoan NAM
Author Information
- Publication Type:Original Article
- Keywords: Respiratory exchange ratio; age-dependency; indirect calorimetry; db/db mouse
- MeSH: Adipose Tissue; Animals; Blood Glucose; Body Weight; Calorimetry, Indirect; Energy Metabolism; Glucose; Heterozygote; Hyperglycemia; Insulin; Insulin Resistance; Leptin; Mice*; Obesity; Rodentia
- From:Laboratory Animal Research 2015;31(1):1-6
- CountryRepublic of Korea
- Language:English
- Abstract: The leptin receptor-deficient db/db mouse is a rodent model of type 2 diabetes and obesity. Diabetes in db/db mice shows an age-dependent progression, with early insulin resistance followed by an insulin secretory defect resulting in profound hyperglycemia. However, there is insufficient data on agedependent changes of energy metabolism in db/db mice. We demonstrated an age-dependent decrease in the respiratory exchange ratio (RER), calculated by a ratio of VO2/VCO2, in db/db mice. The RER determined by indirect calorimetry, was 1.03 in db/db mice under 6 weeks of age, which were similar to those in heterozygote (db/+) and wild-type (+/+) mice. However, RER decreased from approximately 0.9 to 0.8 by 10 weeks of age and subsequently returned to approximately 0.9 at 22 weeks of age. The changes in RER were concurrent with the alterations in body weight and blood glucose level. However, other metabolic indicators such as glucose tolerance, changes in body fat mass, and urinary glucose levels, did not change with age. The results suggested that the energy source utilized in db/db mice changed with the age-related progression of diabetes.
