Effects of anesthesia on the blood glucose of C57/BL6J mice were
evaluated under conditions commonly used for testing retinal sensitivity
with electroretinographic (ERG) recordings. We evaluated the effects of
four anesthetics: nembutal (50 mg/kg), pentothal (100 mg/kg),
avertin (240 mg/kg), and ketamine/xylazine (100 mg/kg) using
saline as control. We measured blood glucose (BG) levels from tail vein
blood before and 15 and 60 min following intraperitoneal injections.
Fifteen minutes postinjection, all four anesthetics and saline elevated BG
with ketamine/xylazine and avertin having substantially greater
effects than nembutal, pentothal, and saline. Only the effects of
ketamine/xylazine and avertin persisted throughout the test period.
Sixty minutes after injecting ketamine/xylazine BG remained elevated
at 400 ± 42 mg/dl, a 167% increase over preinjection levels.
Sixty minutes after injecting avertin BG was 288 ± 10 mg/dl, a
59% increase over preinjection levels. No sustained elevation in BG was
detected 60 min following injection of nembutal, pentothal, or saline.
Because BG can affect the amplitude of the ERG, caution should be
exercised in the use of ketamine/xylazine or avertin. The choice of
anesthesia may also be important in diabetes and metabolism research where
changes in blood glucose could impact physiological processes.