Orignal Paper : Measurement of resting metabolic rate using metabolic chamber in resting rats

Energy expenditure in rats has traditionally been determined based on oxygen uptake using a metabolic chamber. However, using this method, it was difficult to observe the resting metabolic rate (RMR) over 24 h since the adequate flow rate from the room into the chamber was unknown. In this study, we examined the adequate air flow rate for measurement of RMR in rats using an open circuit respirometry system. The adequate air flow rate into the chamber was found to be 3-4 L/min, but a flow rate of 2L/min flow enhanced RMR in rats weighing 250-350 g. We also examined whether or not the RMR measurement method at a room air flow rate of 3-4 L/min is reproducible. The 24 h RMRs over a consecutive 3 day period did not change. Therefore, we carefully concluded that an air flow rate of 3-4 L/min into the metabolic chamber was adequate. These RMR methods can be acceptable for exercise and nutrition science research and may be useful for health sciences research studies, including assessment of foods, exercise training effects, ageing, and obesity research.