title: Circadian rhythm in the effect of theophylline on the behavioral thermoregulation of the white sucker, Catostomus commersoni.
abstract: The temperatures selected by white suckers placed in a thermal gradient were significantly altered by interperitoneal injections of theophylline (25 mg/kg). There was a circadian variation in the effect of theophylline on temperatures selected by individual fish held under constant illumination. Depending on injection time, there was either a significant increase or significant decrease in the temperatures selected. These results are considered in relation to the possible physiological and biochemical effects of theophylline on thermoregulation and circadian rhythms.
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001833:Body Temperature Regulation / Q000187:drug effects*; D002940:Circadian Rhythm; D004305:Dose-Response Relationship, Drug; D005399:Fishes / Q000502:physiology*; D013806:Theophylline / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D013806:Theophylline