DETERMINATION OF THE OXYGEN CONSUMPTION OF GROUPS OF RATS

Abstract

THE metabolic rate of small laboratory animals may be determined by either open or closed circuit respirometers. With the open circuit method, pure atmospheric air is inspired by the animal, then collected and analyzed for either oxygen or carbon dioxide concentration, or both. The composition of the inspired air must also either be known or determined. By difference, the rate of oxygen consumption or carbon dioxide production by the animal can be calculated for the period of observation. This method requires a good source of pure atmospheric air which is often difficult to obtain. A further drawback is the use of certain analytical procedures which are not necessary with the closed circuit system. The closed circuit arrangement has the advantage of permitting: 1) the use of pure oxygen, and 2) the direct measurement of the volume of oxygen consumed by the animal. There are many designs of apparatus of this type (Reineke and Turner, 1950).