Light-dark patterns in running-wheel activity in rats during chronic administration of theophylline.
Running-wheel activity for 24 hr and activity patterns were studied during chronic theophylline administration. Theophylline altered the normal relations between activity level and illumination. Dark-time activity was decreased to approximately 50% and 24 hr activity was unaffected. These observations were consistent with previous results showing that theophylline suppressed dark-time feeding but had no effect on 24 hr food intake. A possible mechanism to account for these results may be dependent on levels and turnover of brain norepinephrine.
D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects*; D003624:Darkness; D008027:Light; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D013806:Theophylline / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
D013806:Theophylline