Biomaterial Database

Administering triazolam on a circadian basis entrains the activity rhythm of hamsters. 1989

O Van Reeth, and F W Turek

Institute of Interdisciplinary Research in Human and Nuclear Biology, Université libre de Bruxelles, Belgium.

A single injection of the short-acting benzodiazepine, triazolam, can induce permanent phase shifts in the circadian rhythm of locomotor activity in free-running hamsters, with the direction and magnitude of the phase shifts being dependent on the circadian time of treatment. The shape of the "phase-response curve" to triazolam injections is totally different from that for light pulses. These findings raise the possibility that repeated injections of triazolam on a circadian basis might be capable of entraining the circadian pacemaker underlying the activity rhythm of hamsters and that the entrainment pattern might differ from that observed in animals entrained to light pulses. To test this hypothesis, blind hamsters received intraperitoneal injections of triazolam (or vehicle) every 23.34, 23.72, 24.00 or 24.66 h for 19-20 days, and the effect of these injections on the period of the rhythm of wheel-running behavior was determined during and after treatment. Repeated injections of 0.1 mg triazolam at these time intervals resulted in the entrainment of the activity rhythm in 36 of 40 animals, whereas 0 of 40 animals entrained to vehicle injections. Importantly, the phase relationship between triazolam injections and the circadian activity rhythm was dependent on the period of drug treatment and could be predicted from the phase-response curve to single injections of triazolam. These phase relationships are dramatically different from those observed between the activity rhythm and 1-h light pulses presented at similar circadian intervals.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008647	Mesocricetus	A genus in the order Rodentia and family Cricetidae. One species, Mesocricetus auratus or golden hamster is widely used in biomedical research.	Hamsters, Golden,Hamsters, Golden Syrian,Hamsters, Syrian,Mesocricetus auratus,Syrian Golden Hamster,Syrian Hamster,Golden Hamster,Golden Hamster, Syrian,Golden Hamsters,Golden Syrian Hamsters,Hamster, Golden,Hamster, Syrian,Hamster, Syrian Golden,Syrian Hamsters
D009043	Motor Activity	Body movements of a human or an animal as a behavioral phenomenon.	Activities, Motor,Activity, Motor,Motor Activities
D001766	Blindness	The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.	Amaurosis,Bilateral Blindness,Blindness, Bilateral,Blindness, Legal,Blindness, Monocular,Blindness, Unilateral,Sudden Visual Loss,Unilateral Blindness,Blindness, Acquired,Blindness, Complete,Blindness, Hysterical,Blindness, Transient,Acquired Blindness,Amauroses,Bilateral Blindnesses,Complete Blindness,Hysterical Blindness,Legal Blindness,Monocular Blindness,Sudden Visual Losses,Transient Blindness,Visual Loss, Sudden
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D006224	Cricetinae	A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.	Cricetus,Hamsters,Hamster
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014229	Triazolam	A short-acting benzodiazepine used in the treatment of insomnia. Some countries temporarily withdrew triazolam from the market because of concerns about adverse reactions, mostly psychological, associated with higher dose ranges. Its use at lower doses with appropriate care and labeling has been reaffirmed by the FDA and most other countries.	Apo-Triazo,Gen-Triazolam,Halcion,Trilam,U-33,030,Apo Triazo,Gen Triazolam,U 33,030,U33,030