Feeding patterns of theophyllinized rats and effects of dextrose on their food intake.

Chronically theophylline administered rats did not show normal increase in food intake during dark periods, while the total amount of intake per 24 hr was not affected. These ingestive results were consistent with changes in arterial-venous blood glucose differences: i.e., those in the control group were markedly dependent on a light-dark feeding cycle, but not those in the theophylline group. Food containing relatively high concentrations of dextrose was found to facilitate food consumption of theophyllinized rats, an effect opposite to that on the controls. These observed changes in the feeding behavior of theophyllinized rats may reflect impaired feeding motivation and circadian desynchronization of feeding.