The CHUM Research Centre (CRCHUM) offers a complete range of services for studying carbohydrate and energy metabolism in rodents. The expertise and turnkey services offered are unique in Canada and enable basic research projects as well as evaluative studies of the effects of compounds/drugs on carbohydrate and energy metabolism using various tools and models in vitro and in vivo.    

Expertise:

• Carrying out research projects at the cellular and tissue levels as well as with animal models.
• Complete metabolic phenotyping of genetically modified rodents.
• Testing the effect of pharmacological or molecular interventions on carbohydrate and energy metabolism in healthy, obese and/or diabetic animal models. 

For all techniques and protocols requiring the use of rodents, standard operating procedures (SOPs) have been established and approved by the CRCHUM’s animal care authority: Comité Institutionnel de Protection des Animaux (CIPA).  In addition, our expertise and knowledge are at your disposal for your experimental design needs and for preparing protocols for CIPA approval.

All our services are turnkey. Surgeries, metabolic tests, dosages and data analysis are performed by our personnel. 

These services are intended for researchers from academic, hospital and industrial settings.

Services
Links with other core facilities
Rates
Information

SERVICES   
Isolation of pancreatic islets
Insulin secretion on cell lines, isolated pancreatic islets (static or dynamic in perifusion) and in situ pancreas
In vivo carbohydrate homeostasis
In vivo energy metabolism
Blood Biochemistry
Experimental models

Isolation of pancreatic islets

Pancreatic islets are isolated by digestion of the pancreas following collagenase injection into the pancreatic canal. Islets are purified by density gradient and hand-picked under a microscope.

Insulin secretion on cell lines, isolated pancreatic islets (static or dynamic in perifusion) and in situ pancreas

These techniques are used to measure insulin secretion in pancreatic beta cells in vitro and ex vivo in response to various secretagogues (glucose, fatty acids, incretins) and/or compounds-drugs.

In vivo carbohydrate homeostasis

• Glucose tolerance tests
  
  This test is commonly used to establish glucose tolerance, i.e., the capacity for normalizing a hyperglycemic episode induced by oral, intraperitoneal or intravenous administration of a glucose bolus in rodents.
  
  
• Insulin tolerance tests
  
  This test is used in rodents to determine insulin sensitivity. The degree of hypoglycemia induced by intraperitoneal or intravenous administration of an insulin bolus is an index of insulin sensitivity.
  
  Tolerance tests involve a complex metabolic response that involves, among other things, insulin secretion and/or insulin sensitivity. When a change in glucose tolerance or insulin sensitivity is suspected using these tests, a quantitative analysis of insulin secretion or insulin sensitivity can be performed using a hyperglycemic clamp and hyperinsulinemic euglycemic clamp respectively.
  
  
• Assessment of insulin secretion by hyperglycemic clamp
  
  The hyperglycemic clamp makes it possible to assess pancreatic beta cell function, i.e., insulin secretion in response to hyperglycemia. The clamp is performed on unrestrained, awake animals. A glucose solution is infused at various rates by means of an intravenous catheter to maintain hyperglycemia at 10, 15 or 20 mM (depending on the study) and monitored on blood samples collected via an arterial catheter. During the test, various blood samples are collected to measure plasma level of insulin and C-peptide over time.
  
  
• Assessment of insulin sensitivity by hyperinsulinemic euglycemic clamp 
   
  The hyperinsulinemic euglycemic clamp makes it possible to quantitatively measure insulin sensitivity in conditions during which glycemia and hyperinsulinemia are set at constant and measurable levels. The clamp is performed on unrestrained, awake animals. A glucose solution is infused simultaneously with insulin intravenously in order to maintain glycemia at a target value (depending on the study). The amount of infused glucose needed to maintain glycemia during a hyperinsulinemic condition is a direct measure of insulin sensitivity.

In vivo energy metabolism

• Body composition
  
  The ECHO MRI is used to measure rodents’ body composition. Fat mass, lean mass, free liquids and total water are measured in less than a minute on awake animals, thereby facilitating longitudinal monitoring of body composition.
  
  
• Metabolic cages
  
  The Accu Scan system is used to non-invasively measure food intake and voluntary locomotive activity in rodents, as well as their oxygen consumption and carbon dioxide production, thereby establishing respiratory quotient and index of use of glucose and lipid substrates.
  
  The Comprehensive Lab Animal Monitoring System (CLAMS) is used for simultaneous and non-invasive measurements in rodents of food intake, water consumption, energy expenditure, respiratory quotient and voluntary locomotive activity. 

Blood Biochemistry

We provide various dosages for metabolites (glucose, fatty acids, triglycerides, lipoproteins), hormones (insulin, C-peptide, GLP-1) and cytokines (leptin, IL1, IL6) from plasma or serum samples.-Experimental models.

Experimental models

We provide several models of obesity (high fat diet, obese Zucker rat) and/or diabetes (pancreatectomy, streptozotocin injection, Goto-Kakizaki rat, db/db obese mouse). In addition, a model of chronic glucose and/or lipid systemic infusion is also available.

LINKS WITH OTHER FACILITIES

Our services are complementary to services offered by the CRCHUM’s cardiovascular core facility, the Centre for Ecogenomic Models of Human Diseases, and its behaviour core facility, making it possible to conduct multidisciplinary research projects.

INFORMATION

For more information about our services, please contact the facility manager:

Thierry Alquier
pheno.metabolique@crchum.qc.ca
(514) 890-8000, ext: 26181