Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Hypoglycemia and Glucagon01:15

Hypoglycemia and Glucagon

Without prolonged fasting, healthy individuals maintain blood glucose levels above 3.5 mM due to a well-adapted neuroendocrine counterregulatory system that effectively prevents acute hypoglycemia, a potentially life-threatening condition. The primary clinical scenarios for hypoglycemia encompass diabetes treatment, inappropriate production of endogenous insulin or insulin-like substances by tumors, and the use of glucose-lowering agents in non-diabetic individuals. Notably, hypoglycemia in the...
Hypoglycemia01:26

Hypoglycemia

Hypoglycemia is a blood glucose level below 70 mg/dL. It commonly occurs in individuals using insulin or insulin-secreting drugs, but may also arise in non-diabetic conditions. People with type 1 diabetes are at the highest risk because they depend on exogenous insulin. People with type 2 diabetes are also at risk, especially when treated with insulin or medications such as sulfonylureas, which increase insulin release regardless of blood glucose levels. It develops when insulin levels exceed...
Hormones Regulating Blood Glucose01:16

Hormones Regulating Blood Glucose

Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced.
In addition to accelerating glucose uptake and utilization, insulin has...
Regulation of Food Intake01:30

Regulation of Food Intake

Short-term regulation of food intake primarily involves neural signals from the gastrointestinal (GI) tract, blood nutrient levels, and GI tract hormones. Communication between the gut and brain via vagal nerve fibers plays a significant role in evaluating the contents of the gut. Clinical studies have shown that protein ingestion produces a more prolonged response in these nerve fibers compared to an equivalent amount of glucose. Additionally, the activation of stretch receptors caused by GI...
Desensitization and Tachyphylaxis01:20

Desensitization and Tachyphylaxis

Tachyphylaxis is described as a rapid decrease in response to a drug after repeated or continuous administration of the same drug dose. It is a phenomenon where the body becomes less responsive to a particular substance or intervention over time, requiring higher doses or stronger interventions to achieve the same effect. It results from adaptive changes in the body's receptors, signaling pathways, or physiological processes that occur in response to prolonged exposure to a stimulus.
Several...
Oral Hypoglycemic Agents: Glinides01:06

Oral Hypoglycemic Agents: Glinides

Repaglinide (Prandin) and Nateglinide (Starlix), known as glinides, are oral insulin secretagogues that stimulate insulin release from pancreatic β cells by closing the ATP-sensitive potassium channels (KATP channel). Repaglinide controls insulin release from pancreatic β cells by managing potassium efflux. It shares two binding sites with sulfonylureas and also has a unique site, indicating overlapping mechanisms of action. With a rapid onset and a 4-7 hour duration, it effectively manages...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Swiss obesity clinical practice guidance.

Swiss medical weekly·2026
Same author

Long-Term Outcomes of Laparoscopic Roux-en-Y Gastric Bypass vs Laparoscopic Sleeve Gastrectomy for Obesity: The SM-BOSS Randomized Clinical Trial.

JAMA surgery·2025
Same author

Central retinal vein occlusion after infliximab therapy in a young patient with ulcerative colitis.

JPGN reports·2024
Same author

Cost of overweight, obesity, and related complications in Switzerland 2021.

Frontiers in public health·2024
Same author

[Medical interventions for the therapy of obesity].

Therapeutische Umschau. Revue therapeutique·2024
Same author

[Obesity and kidney disease].

Therapeutische Umschau. Revue therapeutique·2024
Same journal

Sex-specific mechanisms of childhood trauma-related HPA axis dysregulation: Insights across four regulatory probes.

Psychoneuroendocrinology·2026
Same journal

Prospective daily evidence of cyclic suicidality and self-harm in premenstrual disorders.

Psychoneuroendocrinology·2026
Same journal

Higher plasma catecholamine concentrations in oral cancer patients and association with clinical and psychological characteristics.

Psychoneuroendocrinology·2026
Same journal

Corrigendum to "Cortisol stress reactivity and cumulative output associations with structural neural network architecture in adolescents" [Psychoneuroendocrinology 191 (2026) 107938].

Psychoneuroendocrinology·2026
Same journal

Salivary glucocorticoid receptor gene DNA methylation and cortisol output in relation to lifestyle, psychological distress, and cognition in university students.

Psychoneuroendocrinology·2026
Same journal

Beyond perceived stress: Hair cortisol is linked with cognition and fatigue in black and white patients with multiple sclerosis.

Psychoneuroendocrinology·2026
See all related articles

Related Experiment Video

Updated: Jul 3, 2026

Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice
11:10

Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice

Published on: November 16, 2011

Blocking NMDA receptor signaling does not decrease hormonal counterregulation to hypoglycemia in humans.

Isabel Pais1, Christian Hubold, Manfred Hallschmid

  • 1Department of Internal Medicine I, University of Luebeck, Ratzeburger Allee 160, 23538 Luebeck, Germany. Isabel.Pais@uk-sh.de

Psychoneuroendocrinology
|July 26, 2008
PubMed
Summary
This summary is machine-generated.

Blocking the N-methyl-D-aspartate (NMDA) receptor with memantine did not decrease, but tended to increase, counterregulatory hormone responses to hypoglycemia in humans. This contrasts with animal studies and suggests glutamate signaling does not enforce hormonal counterregulation during low blood sugar.

More Related Videos

Hyperglycemic Clamp and Hypoglycemic Clamp in Conscious Mice
07:35

Hyperglycemic Clamp and Hypoglycemic Clamp in Conscious Mice

Published on: January 26, 2024

Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain
08:32

Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain

Published on: January 4, 2018

Related Experiment Videos

Last Updated: Jul 3, 2026

Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice
11:10

Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice

Published on: November 16, 2011

Hyperglycemic Clamp and Hypoglycemic Clamp in Conscious Mice
07:35

Hyperglycemic Clamp and Hypoglycemic Clamp in Conscious Mice

Published on: January 26, 2024

Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain
08:32

Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain

Published on: January 4, 2018

Area of Science:

  • Neuroendocrinology
  • Metabolic Regulation
  • Neuropharmacology

Background:

  • Glutamate signaling via N-methyl-D-aspartate (NMDA) receptors is crucial for neuroendocrine responses to hypoglycemia in animals.
  • It has been hypothesized that increased glutamatergic input signals central energy demand during low glucose availability.
  • Understanding this mechanism in humans is vital for metabolic and neurological research.

Purpose of the Study:

  • To investigate the effect of the NMDA receptor antagonist memantine on counterregulatory responses to hypoglycemia in healthy humans.
  • To determine if blocking NMDA receptors alters hormonal and symptomatic responses to low blood glucose.
  • To compare human responses to previously observed animal data.

Main Methods:

  • A randomized, placebo-controlled, double-blind study involving 10 healthy men.
  • Hypoglycemic clamp experiments were conducted after oral administration of 20 mg memantine or placebo.
  • Measurement of counterregulatory hormones (adrenocorticotropin, cortisol, epinephrine, norepinephrine, growth hormone, glucagon) and assessment of neuroglycopenic and autonomic symptoms during induced hypoglycemia (2.4 mmol/l for 50 min).

Main Results:

  • Memantine administration did not decrease, but tended to increase, counterregulatory hormone responses (adrenocorticotropin, cortisol, epinephrine) to hypoglycemia.
  • Glucagon levels were elevated by memantine during both baseline and hypoglycemic periods.
  • Subjects reported increased neuroglycopenic symptoms with memantine, while autonomic symptom differences were not significant.
  • Norepinephrine and growth hormone levels remained unaffected by memantine.

Conclusions:

  • Contrary to animal findings, blocking NMDA receptors with memantine does not attenuate counterregulatory responses to hypoglycemia in humans.
  • The results do not support the hypothesis that enhanced glutamate signaling during hypoglycemia enforces hormonal counterregulation to meet central energy demands in humans.
  • This study highlights species-specific differences in the neuroendocrine regulation of glucose metabolism.