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Updated: Aug 10, 2026
Hyperglycemic Clamp and Hypoglycemic Clamp in Conscious Mice
Published on: January 26, 2024
Counterregulatory deficits occur within 24 h of a single hypoglycemic episode in conscious, unrestrained, chronically
Lauren Jacobson1, Tasneem Ansari, Owen P McGuinness
1Center for Neuropharmacology and Neuroscience, Albany Medical College, MC-136, Albany, NY 12208, USA. JACOBSL@mail.amc.edu
Abstract:
Hypoglycemia-induced counterregulatory failure is a dangerous complication of insulin use in diabetes mellitus. Controlled hypoglycemia studies in gene knockout models, which require the use of mice, would aid in identifying causes of defective counterregulation. Because stress can influence counterregulatory hormones and glucose homeostasis, we developed glucose clamps with remote blood sampling in conscious, unrestrained mice. Male C57BL/6 mice implanted with indwelling carotid artery and jugular vein catheters were subjected to 2 h of hyperinsulinemic glucose clamps 24 h apart, with a 6-h fast before each clamp. On day 1, blood glucose was maintained (euglycemia, 178 +/- 4 mg/dl) or decreased to 62 +/- 1 mg/dl (hypoglycemia) by insulin (20 mU x kg(-1) x min(-1)) and variable glucose infusion. Donor blood was continuously infused to replace blood sample volume. Baseline plasma epinephrine (32 +/- 8 pg/ml), corticosterone (16.1 +/- 1.8 microg/dl), and glucagon (35 +/- 3 pg/ml) were unchanged during euglycemia but increased significantly during hypoglycemia, with a glycemic threshold of approximately 80 mg/dl. On day 2, all mice underwent a hypoglycemic clamp (blood glucose, 64 +/- 1 mg/dl). Compared with mice that were euglycemic on day 1, previously hypoglycemic mice had significantly higher glucose requirements and significantly lower plasma glucagon and corticosterone (n = 6/group) on day 2. Epinephrine tended to decrease, although not significantly, in repeatedly hypoglycemic mice. Pre- and post-clamp insulin levels were similar between groups. We conclude that counterregulatory responses to acute and repeated hypoglycemia in unrestrained, chronically cannulated mice reproduce aspects of counterregulation in humans, and that repeated hypoglycemia in mice is a useful model of counterregulatory failure.
Insights
Repeated hypoglycemia in mice impairs counterregulatory hormone responses, mimicking human counterregulatory failure. This study establishes a new model for investigating defective glucose homeostasis in diabetes mellitus.
Area of Science:
- Endocrinology
- Metabolism
- Diabetes Research
Background:
- Hypoglycemia-induced counterregulatory failure is a serious complication of insulin therapy for diabetes mellitus.
- Understanding defective counterregulation requires controlled studies, ideally in models that allow genetic manipulation.
- Stress influences glucose homeostasis and counterregulatory hormones, necessitating methods to minimize stress in study models.
Purpose of the Study:
- To develop and validate a model of controlled, repeated hypoglycemia in conscious, unrestrained mice.
- To investigate the impact of acute and repeated hypoglycemia on counterregulatory hormone responses (epinephrine, corticosterone, glucagon).
- To assess whether repeated hypoglycemia leads to impaired counterregulatory responses, modeling human counterregulatory failure.
Main Methods:
- Developed a glucose clamp technique with remote blood sampling in chronically cannulated, conscious, unrestrained male C57BL/6 mice.
- Subjected mice to two hyperinsulinemic glucose clamps 24 hours apart, with day 1 involving either euglycemia or hypoglycemia, and day 2 involving hypoglycemia for all mice.
- Measured plasma glucose, insulin, epinephrine, corticosterone, and glucagon levels during the clamps.
Main Results:
- Hypoglycemia (approx. 80 mg/dl) significantly increased plasma epinephrine, corticosterone, and glucagon compared to euglycemia.
- Mice subjected to hypoglycemia on day 1 showed significantly higher glucose requirements and lower plasma glucagon and corticosterone on day 2 compared to euglycemic controls.
- Repeated hypoglycemia tended to decrease plasma epinephrine, though not significantly, suggesting an adaptive or suppressive effect.
Conclusions:
- The developed model in unrestrained, cannulated mice effectively reproduces human counterregulatory responses to acute and repeated hypoglycemia.
- Repeated hypoglycemia in this mouse model leads to impaired counterregulatory hormone release, establishing it as a valuable tool for studying counterregulatory failure in diabetes mellitus.
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