Determination of the Total Carbon Dioxide Outputs of Rats By the D2O18 Method

Abstract
The doubly-labeled water (D2O18) method for measuring CO2 output has been tested in eight rats by comparing the value obtained by this procedure with the total CO2 actually collected. The average absolute discrepancy between the two values was 3 (±3)%, and the average discrepancy when account was taken of algebraic sign was +2 (±4)%. (The values in parentheses are standard deviations of the distributions.)