Adrenocortical responses of ducks to treadmill exercise

1982 ◽  
Vol 94 (1) ◽  
pp. 141-146 ◽  
Author(s):  
S. Harvey ◽  
J. G. Phillips
Keyword(s):  
Treadmill Exercise ◽  
Plasma Corticosterone ◽  
Pretreatment Level ◽  
Corticosterone Concentration ◽  
Domestic Ducks ◽  
Corticosterone Secretion ◽  
Corticosterone Response ◽  
Response To Exercise ◽  
Adrenocortical Responses ◽  
Stationary Control

The influence of treadmill exercise on corticosterone secretion has been determined in domestic ducks. In birds unused to such exercise the concentrations of plasma corticosterone were markedly increased (> fourfold) after 15 or 30 min of treadmill exercise (1·1 km/h at 3 ° grade) and the level remained high (between 30 and 40 ng/ml) throughout 90 min of exercise. This increase in corticosterone secretion accompanied a similar increase in colon temperature and was independent of the plasma glucose level. After exercise the corticosterone concentration declined to the pretreatment level within 60 min of recovery. In birds used to the exercise the corticosterone response to a standard (30 min) period of exercise was diminished (by 77·6% in comparison with untrained birds and was no greater than the response (1·7-fold) in stationary control birds after handling and bleeding. The diminution of the corticosterone response to exercise may be due to the trained birds becoming fitter and better able to perform the work involved.

Effect of adenosine analogues on plasma corticosterone concentration in rats

1992 ◽  
Vol 127 (5) ◽  
pp. 471-475 ◽  
Author(s):  
Edmund Przegaliński ◽  
Bogusława Budziszewska ◽  
Anna Grochmal
Keyword(s):  
Adenosine Receptor ◽  
Corticosterone Level ◽  
Plasma Corticosterone ◽  
Receptor Antagonists ◽  
Corticosterone Concentration ◽  
Adenosine Analogues ◽  
Negative Results ◽  
Corticosterone Secretion ◽  
Corticosterone Response ◽  
Pharmacological Blockade

In this study we examined the effect of the adenosine analogues: N6-cyclohexyladenosine, L-N6-phenylisopropyladenosine and 5′-N-ethylcarboxamidoadenosine on the plasma corticosterone concentration in rats. It was found that N6-cyclohexyladenosine (0.1–3.0 mg/kg), L-N6-phenylisopropyladenosine (0.1–1.0 mg/kg) and 5′-N-ethylcarboxamidoadenosine (0.01–1.0 mg/kg) dose-dependently increased the plasma corticosterone level. The effects of N6-cyclohexyladenosine (0.1 mg/kg) and L-N6-phenylisopropyladenosine (0.1 mg/kg) were completely blocked in animals pretreated with dexamethasone (3 × 1 mg/kg), as well as in animals with a pharmacological blockade of the release of hypothalamic corticotropin-releasing factor induced by chloropromazine (10 mg/kg), morphine (20 mg/kg) and nembutal (25 mg/kg), whereas the corticosterone response to 5′-N-ethylcarboxamidoadenosine (0.01 mg/kg) was blocked in dexamethasone-pretreated rats only. On the other hand, the adenosine receptor antagonists: 8-(p-sulfophenyl)-theophylline (30 mg/kg), 8-phenyltheophylline (10 and 30mg/kg), 1,3-dipropyl-8-(2-amino-4-chloro)-phenylxanthine (1 and 3 mg/kg) and 1,3-dipropyl-7-methylxanthine (1 mg/kg) did not affect the corticosterone response to N6-cyclohexyladenosine, L-N6-phenylisopropyladenosine or 5′-N-ethylcarboxamidoadenosine. The obtained results indicate that N6-cyclohexyladenosine and L-N6-phenylisopropyladenosine stimulate the corticosterone secretion at the hypothalamic level, whereas 5′-N-ethylcarboxamidoadenosine is likely to act at the pituitary level. Although the effects produced by the adenosine analogues show that both A1 and A2 receptors are involved in the corticosterone response, negative results of the interaction studies with adenosine receptor antagonists indicate that further experiments are necessary to elucidate this problem.

ANALYSIS OF THE INHIBITION OF THE ACTH RELEASE BY HYPOTHALAMIC IMPLANTS OF ATROPINE

1973 ◽  
Vol 73 (4) ◽  
pp. 651-659 ◽  
Author(s):  
J. Kaplanski ◽  
P. G. Smelik
Keyword(s):  
Adrenal Glands ◽  
Plasma Corticosterone ◽  
Corticosterone Concentration ◽  
Hypothalamic Region ◽  
Adrenal System ◽  
Cholinergic Synapses ◽  
Adrenocortical Responses ◽  
Acth Release

ABSTRACT The effect of anterior hypothalamic atropine implants on the secretion of corticotrophin in the rat, as indicated by the corticosteroid production by adrenal glands incubated in vitro and/or by the plasma corticosterone concentration, was studied. It was found that atropine implants markedly inhibit the adrenocortical responses evoked by all the stress stimuli tested, except for that to a CRF preparation. The onset of the blockade was very fast; the duration of the inhibition lasted for about 2 h. Smaller amounts of atropine (2×15 μg) were also effective when implanted bilaterally into the anterior hypothalamic region. It is concluded that cholinergic synapses in the hypothalamus may be involved in the activation of the pituitary-adrenal system after stressful stimuli.

THE EFFECTS OF HYPOPHYSECTOMY ON ADRENOCORTICAL FUNCTION IN THE DUCK (ANAS PLATYRHYNCHOS)

1971 ◽  
Vol 49 (3) ◽  
pp. 437-457 ◽  
Author(s):  
E. L. BRADLEY ◽  
W. N. HOLMES
Keyword(s):  
Mammalian Species ◽  
Compartment Model ◽  
Liver Glycogen ◽  
Plasma Corticosterone ◽  
Adrenocortical Function ◽  
Metabolic Clearance ◽  
General Effect ◽  
Corticosterone Concentration ◽  
Peripheral Plasma ◽  
Corticosterone Secretion

SUMMARY The general effect of chronic hypophysectomy on organ and body weights, liver glycogen, blood glucose, peripheral plasma corticosterone concentrations, and blood pressure in the duck were similar to those described for several mammalian species. The disappearance and distribution of radioactivity after the administration of [1,2-3H]corticosterone and [1,2-3H]aldosterone was studied according to a single compartment model system. When compared with sham-operated ducks, the apparent volumes of distribution and the biological half-lives of radioactivity in hypophysectomized ducks were significantly increased, and the estimated metabolic clearance rates of [1,2-3H] corticosterone and [1,2-3H]aldosterone were significantly decreased. The patterns of distribution of radioactivity and the rate of metabolism of both hormones returned towards normal when the chronically hypophysectomized ducks were treated with corticotrophin (ACTH). Fourteen days after hypophysectomy the peripheral plasma concentration of corticosterone and the estimated rate of corticosterone secretion by the adrenal fell to 10 and 4%, respectively, of the values observed in sham-operated birds. Examinations of the peripheral plasma corticosterone concentration during the first 30 min after the removal of the adenohypophysis indicated a mean biological half-life for endogenous corticosterone of 13·7 min. The rates of appearance of radioactivity in the bile, intestine and cloaca of the hypophysectomized birds suggested substantial declines in the rates of aldosterone and corticosterone metabolism. These declines could not be accounted for by the reduced rate of glomerular filtration in the hypophysectomized bird. Replacement therapy with ACTH restored the excretory patterns of both steroids towards normal. The quantitative similarities between the effects of hypophysectomy in the duck and several mammalian species make it unnecessary to postulate either a high degree of adrenal autonomy or an extrahypophysial source of ACTH in the control of adrenocortical function in the duck.

Effect of Hippocampal Stimulation on the Plasma Thyrotropin (THS) and Corticosterone Responses to Acute Cold Exposure in the Rat

1972 ◽  
Vol 50 (4) ◽  
pp. 364-367 ◽  
Author(s):  
André Dupont ◽  
Edouard Bastarache ◽  
Elemer Endröczi ◽  
Claude Fortier
Keyword(s):  
Plasma Corticosterone ◽  
Male Rats ◽  
Bipolar Electrode ◽  
Corticosterone Concentration ◽  
Hippocampal Stimulation ◽  
Hippocampal Activity ◽  
Tsh Secretion ◽  
Corticosterone Response ◽  
A Minor ◽  
Stimulation Of

Seven days after the stereotaxic implantation of a bipolar electrode in the gyrus dentatus of the hippocampus of adult male rats, exposure to cold (20 min at −5 °C) increased both plasma TSH and corticosterone concentrations, whereas exposure in association with a minor environmental disturbance (presence of an observer) suppressed the TSH response to cold and enhanced the corticosterone response. Concurrent stimulation of the hippocampus with monophasic square waves of 1.3–1.5 V, 10 c.p.s., and 0.1 ms duration was found to restore the TSH response to cold and to inhibit the secretion of adrenocorticotropin (ACTH) (as reflected by the plasma corticosterone concentration). These findings suggest that the concurrent stimulation of ACTH release and inhibition of TSH secretion induced by nonspecific stress are possibly related to depressed hippocampal activity.

Acute stress- or lipopolysaccharide-induced corticosterone secretion in female rats is independent of the oestrous cycle

1994 ◽  
Vol 131 (5) ◽  
pp. 535-539 ◽  
Author(s):  
Ai-Li Guo ◽  
Felice Petraglia ◽  
Mario Criscuolo ◽  
Guido Ficarra ◽  
Rossella E Nappi ◽  
...  
Keyword(s):  
Acute Stress ◽  
Plasma Corticosterone ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Diurnal Changes ◽  
Experimental Conditions ◽  
Corticotrophin Releasing Factor ◽  
Swimming Stress ◽  
Corticosterone Secretion ◽  
Corticosterone Response

Guo A-L, Petraglia F, Criscuolo M, Ficarra G, Nappi RE, Palumbo M, Valentini A, Genazzani AR. Acute stress- or lipopolysaccharide-induced corticosterone secretion in female rats is independent of the oestrous cycle. Eur J Endocrinol 1994;131:535–9. ISSN 0804–4643 The aim of the present study was to test whether oestrous cycle is associated with the hypothalamus–pituitary–adrenal (HPA) axis function. Thus, corticosterone secretion in rats was investigated following lipopolysaccharide (LPS), acute cold-swimming or ether stress or synthetic corticotrophin-releasing factor (CRF) administration throughout the oestrous cycle. Moreover, plasma corticosterone response to cold-swimming stress or LPS administration also was studied at different times of day on pro-oestrus of di-oestrus-I. The following observations were obtained: the morning plasma corticosterone levels in control rats did not differ with the stage of the oestrous cycle; plasma corticosterone levels increased significantly following LPS administration (2 mg/kg, ip) or following acute exposure to cold (4°C)-swimming or ether stress. However, this increase in plasma corticosterone levels was not related to the stage of the oestrous cycle; synthetic CRF injection induced an increase in plasma corticosterone levels constant on di-oestrus-I and pro-oestrus; plasma corticosterone response to LPS administration or acute cold-swimming stress showed diurnal changes, with the lowest values at 18.00 h. which was independent of the oestrous cycle. By showing the unchanged corticosterone response to LPS, to acute stress and to exogenous CRF throughout the oestrous cycle, and the independence of the diurnal pattern of stress response on the oestrous cycle, the present study suggests that the oestrous cycle has no influence on the HPA activity under the present experimental conditions in rats. Andrea R Genazzani, Department of Obstetrics & Gynecology, University of Modena, Via del Pozzo 71, 41100 Modena, Italy

scholarly journals The effects of fasting on plasma corticosterone kinetics in rats

1991 ◽  
Vol 66 (1) ◽  
pp. 117-127 ◽  
Author(s):  
C. J. H. Woodward ◽  
G. R. Hervey ◽  
R. E. Oakey ◽  
E. M. Whitaker
Keyword(s):  
Binding Capacity ◽  
Plasma Corticosterone ◽  
Corticosterone Concentration ◽  
Corticosterone Secretion ◽  
Fractional Clearance ◽  
Anaesthetized Rats ◽  
Males And Females ◽  
The Mean ◽  
Rate Limiting ◽  
Secretion Rates

Plasma corticosterone clearance in anaesthetized rats was measured from the disappearance of radioactivity after a bolus injection of [3H]corticosterone. Mean fractional clearance rates were significantly (P < 0.05) reduced after a 48 h fast, by 32 and 22% for males and females respectively. Plasma corticosterone concentrations were increased by fasting in both sexes. Corticosterone secretion rates, calculated as the product of fractional clearance and plasma corticosterone concentration, did not differ between fed and fasted groups in either sex. The mean activity (U/liver) of the rate-limiting enzyme for corticosterone degradation, hepatic 4,5-dihydrocorticosterone:NADP+ Δ4-oxidoreductase, was significantly reduced by 51 and 78% after fasting in males and females respectively. This was due to changes in both the soluble and microsomal forms of the enzyme. The binding capacity of corticosterone-binding globulin in plasma was significantly reduced by fasting in females (P < 0.001), but was not altered in males. The results suggest that reduced hormone clearance is the dominant cause of fasting hypercorticosteronaemia in the rat.

PLASMA CORTICOSTERONE CONCENTRATIONS AND PITUITARY PROLACTIN CONTENT IN LATE PREGNANCY AND THEIR WITHIN-DAY FLUCTUATIONS IN THE RAT

1974 ◽  
Vol 61 (1) ◽  
pp. 21-28 ◽  
Author(s):  
KATUAKI ÔTA ◽  
TAKAO ÔTA ◽  
AKIRA YOKOYAMA
Keyword(s):  
Late Pregnancy ◽  
Plasma Corticosterone ◽  
Prolactin Secretion ◽  
Corticosterone Concentration ◽  
Corticosterone Secretion ◽  
Prolactin Content ◽  
Pituitary Prolactin

SUMMARY Levels of plasma corticosterone and of pituitary prolactin were studied in the mornings (10.00–10.30 h) and evenings (17.00–18.00 h) during the last week of pregnancy in the rat. Morning levels of plasma corticosterone started to rise on day 19 and reached a peak on day 21. The concentration of corticosterone in plasma on the morning of day 21 was about 2·3 times higher than that on day 15. Both content and concentration of prolactin in the pituitary began to fall on the morning of day 19 of pregnancy and the minimum values for both content and concentration were reached on the morning of day 21. Plasma corticosterone concentration and pituitary prolactin content measured in the evening, however, remained high throughout the period examined and there were no appreciable changes in the levels at the different stages of pregnancy. The results obtained on day 22 of pregnancy, the expected day of parturition, indicated that a surge of pituitary prolactin secretion and a temporary depression of corticosterone secretion occurred at about the time of parturition.

Effects of progesterone induced postmaturity on CBG and pituitary-adrenal activities in the rat foetus

1986 ◽  
Vol 112 (3) ◽  
pp. 396-403 ◽  
Author(s):  
Jean Paul Dupouy ◽  
Alain Chatelain
Keyword(s):  
Binding Capacity ◽  
Sharp Decrease ◽  
Plasma Corticosterone ◽  
Corticosterone Concentration ◽  
Rat Pups ◽  
Body Weights ◽  
Normal Rat ◽  
Severe Jaundice ◽  
High Level ◽  
Subsequent Rise

Abstract. CBG and pituitary-adrenal activities were investigated in intact rat foetuses, in newborns spontaneously delivered by vaginal way and in postmature foetuses from mothers with delayed parturition caused by daily progesterone injection from day 20 of gestation. The postmature foetuses had lower body weights and higher adrenal weights on day 22, 23 and 24 of gestation than newborns of the same conceptional age. The corticosterone binding capacity of the plasma as well as the binding capacity of CBG for corticosterone decreased in intact foetuses for the last 3 days of gestation and stayed very low in pups from day 0 to day 8 postpartum. These parameters decreased more slowly in postmature foetuses; however, the differences between the latter and intact foetuses or newborns were not statistically significant. Similar evolution occurred in intact pregnant and suckling females as well as in females with prolonged gestation. The fall in CBG activity in normal rat pups and the subsequent rise in free steroids could explain a sharp decrease in plasma ACTH levels as well as the drop in adrenal and plasma corticosterone concentration. In foetuses with prolonged gestation, the same phenomenon did not occur. Stress conditions produced by maintaining growing foetuses in utero and the development of severe jaundice maintained high ACTH levels. In contrast, the fall in adrenal and plasma corticosterone concentrations in spite of the high level of circulating ACTH could be mainly due to the progesterone inhibition of the steroidogenic activity of the foetal adrenals.

Dissociation of adrenal corticosteroid production from ACTH in water-restricted female rats

1981 ◽  
Vol 241 (1) ◽  
pp. R21-R24 ◽  
Author(s):  
R. G. Doell ◽  
M. F. Dallman ◽  
R. B. Clayton ◽  
G. D. Gray ◽  
S. Levine
Keyword(s):  
Corticosterone Level ◽  
Plasma Corticosterone ◽  
Female Rats ◽  
Adrenocorticotrophic Hormone ◽  
Corticosterone Concentration ◽  
Acth Concentration

These experiments were undertaken to investigate the mechanism whereby a precipitous drop in plasma corticosterone concentration is brought about following drinking in rats on a restricted water schedule. No alteration in adrenocorticotrophic hormone (ACTH) output was found, nor was catabolism of corticosterone sufficient to account for the drop. It is concluded that corticosterone level is controlled under these conditions by a mechanism independent of ACTH concentration.

scholarly journals Effects of test experience, closed-arm wall color, and illumination level on behavior and plasma corticosterone response in an elevated plus maze in male C57BL/6J mice: a challenge against conventional interpretation of the test

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Hirotaka Shoji ◽  
Tsuyoshi Miyakawa
Keyword(s):  
Elevated Plus Maze ◽  
Plasma Corticosterone ◽  
Illumination Level ◽  
Test Battery ◽  
Lower Percentage ◽  
Behavioral Tests ◽  
Elevated Plus Maze Test ◽  
Maze Test ◽  
Plus Maze ◽  
Corticosterone Response

AbstractThe elevated plus maze test is a widely used test for assessing anxiety-like behavior and screening novel therapeutic agents in rodents. Previous studies have shown that a variety of internal factors and procedural variables can influence elevated plus maze behavior. Although some studies have suggested a link between behavior and plasma corticosterone levels, the relationships between them remain unclear. In this study, we investigated the effects of experience with a battery of behavioral tests, the wall color of the closed arms, and illumination level on the behavior and plasma corticosterone responses in the elevated plus maze in male C57BL/6J mice. Mice were either subjected to a series of behavioral tests, including assessments of general health and neurological function, a light/dark transition test, and an open field test, or left undisturbed until the start of the elevated plus maze test. The mice with and without test battery experience were allowed to freely explore the elevated plus maze. The other two independent groups of naïve mice were tested in mazes with closed arms with different wall colors (clear, transparent blue, white, and black) or different illumination levels (5, 100, and 800 lx). Immediately after the test, blood was collected to measure plasma corticosterone concentrations. Mice with test battery experience showed a lower percentage of open arm time and entries and, somewhat paradoxically, had lower plasma corticosterone levels than the mice with no test battery experience. Mice tested in the maze with closed arms with clear walls exhibited higher open arm exploration than mice tested in the maze with closed arms with black walls, while there were no significant differences in plasma corticosterone levels between the different wall color conditions. Illumination levels had no significant effects on any measure. Our results indicate that experience with other behavioral tests and different physical features of the maze affect elevated plus maze behaviors. Increased open arm time and entries are conventionally interpreted as decreased anxiety-like behavior, while other possible interpretations are considered: open arm exploration may reflect heightened anxiety and panic-like reaction to a novel situation under certain conditions. With the possibility of different interpretations, the present findings highlight the need to carefully consider the test conditions in designing experiments and drawing conclusions from the behavioral outcomes in the elevated plus maze test in C57BL/6J mice.

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