A Simple Method for Estimating Oxygen Consumption of Small Animals

IN MANY types of experiments it is desirable to measure oxygen consumption of intact experimental animals. Often it is sufficient to observe relative rates of oxygen uptake, without elaborate precautions for the sake of correct absolute values. It is the purpose of the present report to describe a simple apparatus and procedure which combine advantages of certain earlier methods. The apparatus, shown in Figure 1, consists essentially of a large desiccator (10 inches inside diameter) as the animal chamber, gas buret with attached levelling bulb for maintaining atmospheric pressure, and means for providing water-saturated oxygen to the system. The desiccator is painted black for use with non-nocturnal animals, to aid in keeping them in a quiescent state. The procedure, with precautionary comments, is as follows: (a) A 6 inch petri dish containing 40 ml. of 20 percent potassium hydroxide solution is placed in the bottom of the open desiccator. (b) …