Insulin sensitivity tested with a modified euglycemic technique in cats and rats

Area of Science:

• Veterinary Medicine
• Endocrinology
• Pharmacology

Background:

• Insulin resistance is a critical factor in metabolic disorders.
• Accurate assessment of insulin sensitivity is vital for research and clinical applications.
• Existing methods for measuring insulin sensitivity can be invasive or complex.

Purpose of the Study:

• To develop and validate a novel, minimally invasive insulin sensitivity test (IST) for use in preclinical models.
• To establish the sensitivity, reproducibility, and dose-response capabilities of the IST.
• To demonstrate the utility of the IST in detecting acute insulin resistance.

Main Methods:

• A modified euglycemic clamp technique was employed in anesthetized cats and rats.
• Insulin sensitivity was assessed by measuring the glucose infusion rate required to maintain euglycemia.
• A new low-volume blood sampling procedure (0.5 mL) was utilized for frequent glucose monitoring.

Main Results:

• The IST demonstrated sensitivity to insulin dose-response relationships (e.g., 100 mU/kg vs. 50 mU/kg insulin).
• High reproducibility was observed with consecutive tests in cats (%CV = 3.0 +/- 0.5 over 12 hours).
• The test successfully detected atropine-induced insulin resistance, showing dose-response effects.

Conclusions:

• The developed IST is a sensitive, reproducible, and minimally invasive method for assessing insulin sensitivity in rats and cats.
• This test is suitable for demonstrating acute insulin resistance and dose-response relationships in preclinical research.
• The IST offers a practical alternative for insulin sensitivity testing in animal models.