Insulin Tolerance Test
Insulin Tolerance Test - Related Videos
08:13
Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test (OGTT) and Insulin Tolerance Test (ITT)
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Cited by 151 •
2018
The current article describes the generation and metabolic characterization of high-fat diet-fed mice as a model of diet-induced insulin resistance and obesity. It further features detailed protocols to perform the oral glucose tolerance test and the insulin tolerance test, monitoring whole-body alterations of glucose metabolism in vivo.
06:59
Characterization of Metabolic Status in Nonhuman Primates with the Intravenous Glucose Tolerance Test
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Cited by 7 •
2016
The goal of this protocol is to present a standard method to perform intravenous glucose tolerance tests (IVGTTs) to assess glycemic control in nonhuman primates and assess their metabolic status from healthy to dysmetabolic.
05:52
Insulin Injection and Hemolymph Extraction to Measure Insulin Sensitivity in Adult Drosophila melanogaster
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Cited by 16 •
2011
Conserved insulin signaling pathways found in the fruit fly Drosophila melanogaster make this organism a potential tool for modeling metabolic disorders including type II diabetes. To this end, it is critical to establish physiological assays to effectively measure systemic insulin action in peripheral glucose disposal in the adult fly.
02:23
Oral Glucose Tolerance Test (OGTT): Measuring Glucose Metabolism in Mice
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2023
This video introduces how to perform an oral glucose tolerance test on a laboratory mouse.
01:17
Salinity Tolerance of Alishewanella Species Isolated from Seawall Muddy Water
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2025
Begin with a culture of Alishewanella, a Gram-negative, salt-tolerant bacterium.Next, streak the culture onto agar plates containing increasing concentrations of sodium chloride to simulate varying levels of saline stress.Overlay each plate with a layer of unsolidified medium to prevent oxygen diffusion and maintain the culture in an oxygen-limited environment.Seal and incubate the plates at an optimum temperature to support bacterial growth.During incubation, the bacterium exhibits varying...
FAQs
The induced glucose decline creates a controlled metabolic challenge that reveals how effectively counterregulatory systems respond. Serial glucose measurements show the course of metabolic recovery, while hormone measurements indicate whether neuroendocrine pathways become activated during the challenge. This makes the test useful for examining physiological coordination between glucose regulation and stress-related endocrine signaling.
Glucose values describe the metabolic disturbance and subsequent recovery, whereas ACTH, cortisol, and corticosterone provide information about endocrine responses to that disturbance. Considering these measurements together helps investigators evaluate activation of counterregulatory pathways rather than relying on glucose concentration alone. The resulting profile can clarify how metabolic and hormonal responses are coordinated.
Insulin-induced hypoglycemia challenges systems that regulate energy availability, allowing researchers to examine hypothalamic participation in the response. Changes in glucose recovery and associated hormone release can be interpreted in the context of hypothalamic regulation of energy balance. In neuroscience studies, this links metabolic sensing with broader neuroendocrine control rather than treating glucose regulation as an isolated process.
A single measurement cannot show whether glucose is recovering or whether hormone activation changes as the challenge progresses. Serial sampling captures both the direction of glucose change and the evolving responses of ACTH, cortisol, or corticosterone. This time-dependent information helps distinguish the initial effect of insulin from the subsequent metabolic and neuroendocrine recovery process.
The procedure begins under controlled conditions with insulin administration, followed by repeated assessment of blood glucose and selected hormones. Measurements are collected across the induced hypoglycemic challenge so investigators can track both metabolic recovery and counterregulatory activation. Standardized recovery measures are then used because the glucose reduction can become severe and requires active oversight.
Because insulin can produce severe hypoglycemia, the subject requires continuous, careful monitoring throughout the challenge and recovery period. Glucose measurements help track the physiological state, while standardized recovery measures provide a defined response when the test ends or recovery is needed. These precautions are essential for obtaining interpretable data without neglecting the risks of the procedure.
Researchers use the test to investigate hypothalamic regulation of energy balance, stress responses, and the hypothalamic-pituitary-adrenal axis. It can also help assess endocrine function after disruptions involving the brain or pituitary. Comparing glucose recovery with ACTH, cortisol, or corticosterone responses provides context for determining whether altered neural or pituitary function affects coordinated neuroendocrine regulation.