Biomaterial Database

[Hypothalamo-pituitary-adrenocortical (HPA) function in the morphine dependent rat (author's transl)]. 1979

M Kuki

Morphine dependence was induced by ten daily administrations of morphine with gradually increasing dosage (40--160 mg/kg/day s.c.) to male Sprague-Dawley rats, the dosage being divided in 2/day for the first 8 days and 4/day for the last 2 days. Diurnal variation in body weight in morphine dependent rats was the same as in naive rats. Although body temperature in the naive rats showed a diurnal variation with the highest at 3:00 and the lowest at 15:00, in the morphine dependent rats there was no distinct variation. Plasma corticosterone level (PC) in naive rats showed diurnal variation with the peak at 21:00 and the trough at 9:00. PC in morphine dependent rats showed the same diurnal variation as did the naive rats, while such disappeared following pentobarbital anesthesia (80 mg/kg i.p. for 45 min) and PC was low all during the day. The PC increase following formalin administration to morphine dependent rats was higher than in naive rats. 0.1 mg/kg s.c. of dexamethasone completely inhibited PC increase after formalin in naive rats, but the dexamethasone inhibition in morphine dependent rats was not complete even with a larger dose, i.e. 10 mg/kg s.c. Diurnal variations and other differences were not detected in the adrenal response to ACTH (in vivo, in vitro) between naive and morphine dpendent rats. These results suggest that HPA function takes part in the development of morphine dependence.

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
D009021	Morphine Dependence	Strong dependence, both physiological and emotional, upon morphine.	Morphine Abuse,Morphine Addiction,Abuse, Morphine,Addiction, Morphine,Dependence, Morphine
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
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
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
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)
D003864	Depression, Chemical	The decrease in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.	Chemical Depression,Chemical Depressions,Depressions, Chemical
D003907	Dexamethasone	An anti-inflammatory 9-fluoro-glucocorticoid.	Hexadecadrol,Decaject,Decaject-L.A.,Decameth,Decaspray,Dexasone,Dexpak,Hexadrol,Maxidex,Methylfluorprednisolone,Millicorten,Oradexon,Decaject L.A.