Gold Standard Metabolic Phenotyping

At the Monash Metabolic Phenotyping Platform, our gold standard metabolic phenotyping tests combine arterial and jugular vein cannulation with radioisotopes to look at whole body insulin action, glucose sensitivity and the metabolic response to treadmill exercise. In addition, the rates of glucose and/or fatty acid uptake by multiple tissue can be assessed.

All tests are performed in conscious and unrestrained mice. These are considered to be the gold standard for examining metabolism in vivo. We can undertake several procedures on your behalf, including:

• Hyperinsulinaemic-euglycaemic clamp: assesses whole body insulin action and the ability of insulin to suppress hepatic glucose production. Rates of glucose uptake by multiple tissues can also be assessed.
• Hyperglycaemic clamp: assesses blood metabolite and hormone responses to an acute elevation in blood glucose levels.
• Hyperinsulinaemic-hypoglycaemic clamp: assesses the counter regulatory response to an acute drop in blood glucose levels via insulin.
• Metabolic response to exercise: assesses endogenous glucose production and/or rates of glucose uptake by multiple tissues.

Should you require us to perform a procedure not listed here, we are more than happy to discuss your requirements and the feasibility of performing your procedure through our platform.

Hyperinsulinaemic-Euglycaemic Clamp

We performed a hyperinsulinaemic-euglycaemic clamp (termed insulin clamp) in two groups of C57BL/6J mice. One group of mice (Group A; n=9) were injected with saline 3 hours prior to the insulin clamp (4mU/kg/min insulin), while a second group of mice (Group B; n=7) were injected with a drug 3 hours prior to the insulin clamp.

As shown in Figure A below, blood glucose levels were kept similar between groups. However, the rate of glucose infusion (GIR) required to keep blood glucose levels similar was lower in Group B (Figure B). This was due to an impairment in the suppression of endogenous glucose production in response to insulin (R; Figure C), as well as an impairment in whole-body glucose disposal in response to insulin (Rd; Figure D). Data are presented as mean ± standard deviation (A, B) or as a scatter plot (C, D; bars denote mean ± standard deviation). * p<0.05 vs. Group 1.