Biomaterial Database

Circadian rhythm of thermoregulating responses in man exposed to thermal stimuli. 1982

H Marotte, and J Timbal

Circadian changes in man's thermoregulating responses were studied in two experimental runs during which 7 volunteer subjects were exposed at 8 equally spaced time points of the 24-h span to a quick rise in temperature (To = 40 degrees C, v = 1 m/sec, P H2O less than 1 kPa) or to progressive cooling, the final temperature being reached after 45 min (To = 20 degrees C, v = 0.2 m/sec, P H2O less than 1 kPa). Under heat exposure, a circadian rhythm was observed in the period preceding the onset of sweating, and also in rectal temperature and mean body temperature, both at the onset of sweating and at its steady state. The time constant of the sweating rate and the sweating rate at the steady state show no apparent changes. Under cold exposure there is no detectable circadian rhythm in the mean body temperature at the onset of shivering, however, a circadian evolution appears in rectal temperature at the onset of shivering and at the end of the experiment. A circadian rhythm also appears for the metabolic response at the end of the experiment. These results suggest the presence of a circadian rhythm of the set point with no change in the gain of sweat responses. They also imply that thermoregulating responses to cold follow circadian changes.

UI	MeSH Term	Description	Entries
D012007	Rectum	The distal segment of the LARGE INTESTINE, between the SIGMOID COLON and the ANAL CANAL.	Rectums
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
D001833	Body Temperature Regulation	The processes of heating and cooling that an organism uses to control its temperature.	Heat Loss,Thermoregulation,Regulation, Body Temperature,Temperature Regulation, Body,Body Temperature Regulations,Heat Losses,Loss, Heat,Losses, Heat,Regulations, Body Temperature,Temperature Regulations, Body,Thermoregulations
D002151	Calorimetry	The measurement of the quantity of heat involved in various processes, such as chemical reactions, changes of state, and formations of solutions, or in the determination of the heat capacities of substances. The fundamental unit of measurement is the joule or the calorie (4.184 joules). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
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
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012768	Shivering	Involuntary contraction or twitching of the muscles. It is a physiologic method of heat production in man and other mammals.	Shiverings
D012881	Skin Temperature	The TEMPERATURE at the outer surface of the body.	Skin Temperatures,Temperature, Skin,Temperatures, Skin
D013546	Sweating	The process of exocrine secretion of the SWEAT GLANDS, including the aqueous sweat from the ECCRINE GLANDS and the complex viscous fluids of the APOCRINE GLANDS.