Evaluating the glucose tolerance test in mice

Abstract

The objective of this study was to determine the optimal conditions under which to assess glucose tolerance in chow- and high-fat-fed C57BL/6J mice. Mice were fed either chow or high-fat diet for 8 wk. Variables tested were fasting duration (0-, 3-, 6-, and 24-h and overnight fasting), route of administration (intraperitoneal vs. oral) load of glucose given (2, 1, or 0.5 g/kg and fixed 50-mg dose), and state of consciousness. Basal glucose concentrations were increased in high-fat- compared with chow-fed mice following 6 h of fasting (9.1 +/- 0.3 vs. 7.9 +/- 0.4 mmol/l P = 0.01). Glucose tolerance was most different and therefore significant (P = 0.001) in high-fat-fed mice after 6 h of fasting (1,973 +/- 96 vs. 1,248 +/- 83 mmol.l(-1).120 min(-1)). The difference in glucose tolerance was greater following an OGTT (142%), in contrast to an IPGTT, with a 127% difference between high fat and chow. We also found that administering 2 g/kg of glucose resulted in a greater level of significance (P = 0.0008) in glucose intolerance in high-fat- compared with chow-fed mice. A fixed dose of 50 mg glucose regardless of body weight was enough to show glucose intolerance in high-fat- vs. chow-fed mice. Finally, high-fat-fed mice showed glucose intolerance compared with their chow-fed counterparts whether they were tested under conscious or anesthetized conditions. We conclude that 2 g/kg glucose administered orally following 6 h of fasting is best to assess glucose tolerance in mice under these conditions.

Amaranth Protein Improves Lipid Profile and Insulin Resistance in a Diet-induced Obese Mice Model

“…For body weight measurements, the sample size was calculated assuming a minimum detectable difference of 30% [18] , a desired statistical power of 0.8, and an alpha error of 0.05 for an ANOVA analysis using the sample size calculator from SigmaPlot 12.3 software (Systat Inc., Chicago, IL, USA). The statistical analysis was performed through a one-way analysis or a two-way analysis (in the case of time course of blood glucose) of variance (ANOVA) with a Holm-Sidak post-hoc test using the analysis tool from SigmaPlot 12.3 software (Systat Inc., Chicago, IL, USA).…”

“…One day before the end of the experiment, a glucose tolerance test was performed with a glucose dose of 2 mg/kg and a fasting period of 6 h using a FreeStyle glucometer (Abbott Diabetes Care, Almeda, CA, EUA), as described previously by Andrikopoulos et al [18]. At the end of the experimental period mice were anesthetized, blood was collected by retro-orbital punction and the epididymal adipose tissue (EAT) was collected after euthanasia.…”

AICAR ameliorates high-fat diet-associated pathophysiology in mouse and ex vivo models, independent of adiponectin

“…Mice were randomly assigned in consecutive order to an SFD or HFD, and to vehicle or AICAR treatment. At week 11, we performed a fasted IPGTT [30] and collected urine for 24 h to assess microalbuminuria and urine H 2 O 2 levels. At the end of the study, WAT and kidney leucocytes were isolated and characterised by flow cytometry.…”

Role of glycogen metabolism in pancreatic islet beta cell function

“…Second, in both control and PTG OE mice no significant change in insulinaemia was observed during the IPGTT at zero vs 30 min [1], whereas, under identical experimental conditions in normal mice, insulinaemia peaks at 30 min after i.p. administration of 2 g glucose/kg body weight [15]. In respect of this, Mir-Coll et al refer to a prior publication in which, at least in hepatocytes, PTG modifies glycogen phosphorylase phosphorylation and activity [1].…”