Alterations in glucose kinetics induced by pentobarbital anesthesia

Area of Science:

• Physiology
• Endocrinology
• Pharmacology

Background:

• Pentobarbital is frequently used in carbohydrate metabolism research.
• The in vivo effects of pentobarbital on glucose homeostasis require elucidation.
• Anesthesia can influence physiological parameters critical to metabolic studies.

Purpose of the Study:

• To investigate the in vivo effect of pentobarbital on glucose homeostasis in rats.
• To determine the role of body temperature in pentobarbital-induced metabolic changes.

Main Methods:

• Glucose kinetics were assessed using constant intravenous infusion of labeled glucose ([6-3H]- and [U-14C]glucose).
• Studies were conducted in conscious, anesthetized (temperature-maintained), and anesthetized (uncontrolled temperature) fasted rats.
• Physiological parameters (blood pressure, heart rate, plasma lactate) and glucose metabolism were measured.

Main Results:

• Hypothermic anesthetized rats exhibited decreased mean arterial blood pressure and heart rate.
• Hypothermia significantly reduced plasma lactate concentration and glucose metabolism (appearance, recycling, clearance rates) by 30-50%.
• These metabolic alterations were absent in euthermic anesthetized rats and conscious rats.

Conclusions:

• Pentobarbital-induced hypothermia, not the drug itself, is primarily responsible for reduced glucose metabolism.
• Maintaining body temperature during pentobarbital anesthesia is crucial for accurate studies of carbohydrate metabolism.
• Hypothermia significantly impairs glucose kinetics and carbohydrate metabolism in rats.