Biomaterial Database

The effects of chronic cold exposure on diurnal corticosterone and aldosterone rhythms in Sprague-Dawley rats. 1993

M E Bligh-Tynan, and S A Bhagwat, and T W Castonguay

Department of Human Nutrition and Food Systems, University of Maryland, College Park 20742.

Plasma corticosterone (CORT) and aldosterone (ALDO) exhibit diurnal rhythmicity. Cold exposure increases basal plasma CORT and ALDO levels. This study investigated the effects of cold exposure on CORT and ALDO diurnal rhythms. Twelve male Sprague-Dawley rats were housed at 23 degrees C, adapted to a 12:12 day:night cycle (lights on 0900 h), and provided chow and water ad lib. On day 7, 100 microliters tail blood samples were obtained every 4 h for 24 h beginning at 0900 h. The temperature of the animal room was lowered to 4 degrees C. On days 7 and 14 of cold exposure, blood samples were obtained every 4 h as above. After 7 days at 4 degrees C, CORT levels were elevated at 0900 h, 1300 h, and 0500 h (p < 0.05) as compared to levels observed at 23 degrees C. Peak CORT levels were observed at 2100 h in each 24-h sampling session with mean levels of 181.3 +/- 23.3 ng/ml at 23 degrees C, and 200.5 +/- 16.4 ng/ml and 188.1 +/- 19.9 ng/ml after 7 and 14 days at 4 degrees C. In contrast, ALDO levels were elevated at all time points across the day:night cycle after 7 days at 4 degrees C. After 14 days, ALDO levels were elevated at 0900 h, 1300 h, and 2100 h (p < 0.05) as compared to levels observed at 23 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007030	Hypothalamo-Hypophyseal System	A collection of NEURONS, tracts of NERVE FIBERS, endocrine tissue, and blood vessels in the HYPOTHALAMUS and the PITUITARY GLAND. This hypothalamo-hypophyseal portal circulation provides the mechanism for hypothalamic neuroendocrine (HYPOTHALAMIC HORMONES) regulation of pituitary function and the release of various PITUITARY HORMONES into the systemic circulation to maintain HOMEOSTASIS.	Hypothalamic Hypophyseal System,Hypothalamo-Pituitary-Adrenal Axis,Hypophyseal Portal System,Hypothalamic-Pituitary Unit,Hypothalamic Hypophyseal Systems,Hypothalamic Pituitary Unit,Hypothalamo Hypophyseal System,Hypothalamo Pituitary Adrenal Axis,Portal System, Hypophyseal
D008297	Male		Males
D010913	Pituitary-Adrenal System	The interactions between the anterior pituitary and adrenal glands, in which corticotropin (ACTH) stimulates the adrenal cortex and adrenal cortical hormones suppress the production of corticotropin by the anterior pituitary.	Pituitary Adrenal System,Pituitary-Adrenal Systems,System, Pituitary-Adrenal,Systems, Pituitary-Adrenal
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
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
D003345	Corticosterone	An adrenocortical steroid that has modest but significant activities as a mineralocorticoid and a glucocorticoid. (From Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1437)
D004734	Energy Metabolism	The chemical reactions involved in the production and utilization of various forms of energy in cells.	Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
D000064	Acclimatization	Adaptation to a new environment or to a change in the old.	Acclimation
D000450	Aldosterone	A hormone secreted by the ADRENAL CORTEX that regulates electrolyte and water balance by increasing the renal retention of sodium and the excretion of potassium.	Aldosterone, (+-)-Isomer,Aldosterone, (11 beta,17 alpha)-Isomer
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