Light-dark patterns in running-wheel activity in rats during chronic administration of theophylline

Is regulation of body weight elucidated

A new perspective on mechanisms involved in the regulation of a constant fat body mass and its relation to body energy balance is presented on the basis of a series of experiments. A study of the neuroendocrine conditions underlying the daily weight gain-weight loss cycle in rat and man and experimentally induced over and underweight, leads to the notion that lipogenesis and lipolysis above and below a range of physiological fluctuations of body fat develop a counter-regulatory tendency to correcting lipolysis and lipogenesis respectively. This development is attributed to a chronic central action of plasma insulin concentration on hypothalamic insulin receptors. This liporegulatory system which controls and regulates the filling and emptying of fat stores modulates the feeding system which controls and regulates the filling of a gastrointestinal store by eating and its emptying by metabolic food utilization.

Theophylline delays human sleep phase

Twelve healthy male volunteers were given theophylline 250 mg in order to test effects on 24-hr rhythms. Rhythms of sleep/wake and subjective sleepiness were delayed. Ingestion of xanthines such as theophylline in coffee, tea, colas and chocolate may contribute to some sleep disorders. Theophylline might likewise be useful in treating disorders of circadian oscillators.