Related Experiment Video
Updated: Jul 13, 2026

Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice
Published on: November 16, 2011
Caffeine's impairment of insulin-mediated glucose disposal cannot be solely attributed to adrenaline in humans
D S Battram1, T E Graham, F Dela
1Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1. dbattram@uwo.ca
Abstract:
Caffeine (CAF) impedes insulin-mediated glucose disposal (IMGD) and increases plasma adrenaline concentrations ([ADR]; 0.6 nm). While the antagonism of ADR abolishes the CAF effect, infusion of ADR (0.75 nm) has no effect on IMGD. We have now examined CAF and ADR in concert to determine whether or not they elicit an additive response on IMGD. We hypothesized that CAF + ADR would elicit a greater effect than either CAF or ADR alone (i.e. that CAF effects would not be solely attributed to ADR). Subjects (n = 8) completed four trials in a randomized manner. An isoglycaemic-hyperinsulinaemic clamp was performed 30 min after the following treatments were administered: (1) placebo capsules and saline infusion ([ADR] = 0.29 nm) (PL trial), (2) CAF capsules (dose = 5 mg kg(-1)) and saline infusion ([ADR] = 0.62 nm) (CAF trial), (3) PL capsules and ADR infusion ([ADR] = 1.19 nm) (ADR trial), and (4) CAF capsules (dose = 5 mg kg(-1)) and ADR infusion ([ADR] = 0.93 nm) (CAF + ADR trial). As expected, CAF, ADR and CAF + ADR decreased (P
More Related Videos
Related Concept Videos
Hormones Regulating Blood Glucose
In addition to accelerating glucose uptake and utilization, insulin has...
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
Insulin and C-peptide are co-secreted in...
Hypoglycemia and Glucagon
Glucose Homeostasis: Regulation of Blood Glucose
During fasting, when blood glucose levels are low, the pancreas secretes glucagon. it...
Adrenergic Agonists: Mixed-Action Agents
Ephedrine and pseudoephedrine lack a catecholamine group, making them less susceptible to degradation by metabolic enzymes. They have increased oral bioavailability and lipophilicity, resulting in a longer duration of action. Their response is reduced by...
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...

