A sensitive direct calorimeter for small mammals

A sensitive direct calorimeter for small animals is presented. Its principle is based on the measurement of the heat transfer from the animal chamber to a heat sink. The system gives repetitive measurements with a high efficiency and allows a detailed time-related measurement of the heat production by the whole animal. Its low response time can be advantageously used for the study of post-prandial heat generation and diet-induced thermogenesis. Data on the heat production by Wistar and lean and obese Zucker rats is also included.