Biomaterial Database

Independence of heart rate and circadian period in the golden hamster. 1993

R Refinetti, and M Menaker

Department of Biology, University of Virginia, Charlottesville 22901.

Cardiac contractions are under the influence of at least two processes of biological timing, one responsible for the mean level of heart rate (oscillations with a frequency of up to several hundred per minute) and another responsible for the circadian rhythm of heart rate (oscillations with a frequency of one per 24 h). To investigate whether the mean level of heart rate is proportional to the frequency of circadian oscillation, we compared the heart rates of normal golden hamsters (circadian period approximately 24 h) and tau-mutant hamsters (circadian period approximately 20 h). Neither in anesthetized preparations nor in freely moving animals was there a difference in heart rate between the two groups despite the 20% difference in circadian period. Thus the mean level of heart rate seems to be independent of the circadian period. It is likely that the tau gene, which affects the frequency of the circadian pacemaker, has no effect on the intrinsic frequency of the cardiac pacemaker. In vitro studies of isolated hearts or myocardial cell cultures are necessary to confirm this inference.

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
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D001831	Body Temperature	The measure of the level of heat of a human or animal.	Organ Temperature,Body Temperatures,Organ Temperatures,Temperature, Body,Temperature, Organ,Temperatures, Body,Temperatures, Organ
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
D005838	Genotype	The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.	Genogroup,Genogroups,Genotypes
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
D006339	Heart Rate	The number of times the HEART VENTRICLES contract per unit of time, usually per minute.	Cardiac Rate,Chronotropism, Cardiac,Heart Rate Control,Heartbeat,Pulse Rate,Cardiac Chronotropy,Cardiac Chronotropism,Cardiac Rates,Chronotropy, Cardiac,Control, Heart Rate,Heart Rates,Heartbeats,Pulse Rates,Rate Control, Heart,Rate, Cardiac,Rate, Heart,Rate, Pulse
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