Substrate preference in aminophylline-stimulated thermogenesis.

The present study investigated the suitability of different substrates on aminophylline (AMPY)-induced thermogenesis in rats during cold exposure. Feeding of distilled water 60 min prior to cold exposure in two-day fasted rats resulted in the lowest total heat production and final body temperature in both saline- and AMPY-treated groups. Feeding of 5 ml Intralipid (2 Kcal/ml), a triglyceride mixture, did not improve thermogenesis beyond the control levels. However, feeding of isocaloric substitutes of sucrose elevated significantly the total thermogenesis by 7.9% and 7.4% and final body temperature by 2.23 and 1.61 degrees C, respectively, in saline- and AMPY-treated groups. The increase in thermogenesis by sucrose is not due to its thermic effect. It is concluded that sucrose, in combination with AMPY, may be of value in improving resistance to cold.