Antimetabolic Extract from the Brain of the Hibernating Ground Squirrel Citellus tridecemlineatus

Abstract
Extracts of subcortical brains from hibernating ground squirrels, when injected intravenously into rats, caused a mean decrease in oxygen consumption of 35 percent and a decline in body temperature of 5 degree C. The effects lasted from 75 minutes to 30 hours. Brain extracts of nonhibernating squirrels caused no significant changes in these parameters.