Kidney function in mice: thiobutabarbital versus alpha-chloralose anesthesia

Area of Science:

• Nephrology
• Anesthesiology
• Physiology

Background:

• Investigating gene function often requires precise measurements of kidney function in mice.
• Anesthesia is necessary for techniques like micropuncture and inulin clearance but can affect kidney function.
• Choosing an appropriate anesthetic is vital for maintaining stable glomerular and tubular function during experiments.

Purpose of the Study:

• To compare the effects of thiobutabarbital (TBB) and alpha-chloralose (CHL) anesthesia on blood pressure, heart rate, and kidney function in mice.
• To assess the stability of kidney function under TBB versus CHL anesthesia during clearance experiments.

Main Methods:

• Male CD1 mice were anesthetized with either TBB (100 mg/kg i.p.) or CHL (120 mg/kg i.p.), with ketamine for analgesia.
• Glomerular filtration rate (GFR) and fractional excretion of fluid, Na+, and K+ were measured over two 30-minute periods (P1 and P2) using clearance techniques.
• Hemodynamic parameters (heart rate, mean arterial blood pressure) were monitored.

Main Results:

• Both TBB and CHL anesthesia maintained stable heart rate and mean arterial blood pressure.
• CHL anesthesia demonstrated stable GFR and fractional excretion of fluid, Na+, and K+ from P1 to P2.
• TBB anesthesia showed a higher initial GFR and significantly increased fractional excretion of fluid and Na+ in P2 compared to P1, indicating less stable kidney reabsorption.

Conclusions:

• Both TBB and CHL provide adequate anesthesia for mouse kidney function studies with stable hemodynamics.
• Alpha-chloralose (CHL) anesthesia offers superior stability in kidney reabsorption compared to thiobutabarbital (TBB).
• CHL anesthesia is recommended for studies requiring stable kidney function, particularly when investigating responses to acute interventions.