The effect of 6-hydroxydopamine infused into the third cerebral ventricle on the plasma cortisol concentration in sheep subjected to repeated and prolonged stress stimuli

1985 ◽  
Vol 110 (4) ◽  
pp. 546-552 ◽  
Author(s):  
E. Domański ◽  
E. Stupnicka ◽  
F. Przekop ◽  
E. Wolińska-Witort
Keyword(s):  
Circadian Rhythm ◽  
Cortisol Level ◽  
Plasma Cortisol ◽  
Plasma Cortisol Level ◽  
Cortisol Concentration ◽  
Cortisol Secretion ◽  
The Third ◽  
Plasma Cortisol Concentration ◽  
6 Hydroxydopamine ◽  
Prolonged Stress

Abstract. It has previously been observed that sheep subjected to repeated and prolonged stress stimuli showed biphasic cortisol responses. On the first and second day of stimulation an elevation was observed, while on the subsequent days and on the day after the stimulation a marked suppression of plasma cortisol level and a disappearance of its circadian rhythm was noted. It was hypothesized that these changes in the secretion of the hormone were caused by the alteration of catecholaminergic systems in the CNS. To verify this suggestion chemical lesions of the catecholergic systems of the diencephalon were carried out by the infusion of 6-hydroxydopamine (6-OHDA) into the third cerebral ventricle and animals treated in this fashion were subjected to repeated and prolonged electrical mild footshocking (applied during 3 days). The pretreated animals lost the circadian rhythm in cortisol secretion on the days before as well as during and after the electrical stimulation. The animals pretreated with 6-OHDA showed a significant rise of the plasma cortisol level during stimulation. This rise, as the highest daily concentration, occurring within about 1 h after the beginning of footshocking, was significantly accelerated in time with respect to the physiological acrophase, occurring in the early morning hours at the end of prestimulatory days. On the other hand, the pretreated animals did not show the decrease of plasma cortisol levels on the day after the stimulation, observed in normal non-pretreated ones. It is suggested that the absence of the suppression of plasma cortisol concentration in the animals pretreated with 6-OHDA on the day after the stimulation may be due to the blockade of the ventral noradrenergic bundle innervating the medial basal hypothalamus, while disappearance of the circadian rhythm of cortisol secretion was due to the disturbance in the function of retinohypothalamic projection.

Changes in circadian rhythm and suppression of the plasma cortisol level after prolonged stress in the sheep

1985 ◽  
Vol 110 (4) ◽  
pp. 540-545 ◽  
Author(s):  
F. Przekop ◽  
E. Stupnicka ◽  
E. Wolińska-Witort ◽  
K. Mateusiak ◽  
B. Sadowski ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Cortisol Level ◽  
Plasma Cortisol ◽  
Plasma Cortisol Level ◽  
Diurnal Variations ◽  
Cortisol Response ◽  
Time Of Application ◽  
Prolonged Stress ◽  
Similar Decrease ◽  
Stimulation Of

Abstract. Diurnal variations in the plasma cortisol level were studied in anoestrous, pro-oestrous and pregnant ewes subjected to weak electric stimulation of the forelimbs 9 h daily for 3 consecutive days. In non-pregnant ewes the cortisol level rose on each of the 3 days when the stimulation was applied and then decreased on the day following the stimulation. A similar decrease in plasma cortisol concentrations in pregnant ewes appeared on the second day of footshocking. The acrophase of the circadian rhythm on electrostimulation days was synchronous with the time of application of footshocks; therefore, in stimulated ewes it was significantly accelerated compared to the prestimulatory day. A decrease in the plasma cortisol level in pro-oestrous and pregnant ewes was accompanied by disappearance of its normal rhythmicity. Since a normal plasma cortisol response to exogenous corticotrophin was noted after 3 days of foot-shocking it seems unlikely that the decrease in the cortisol level after prolonged stress was caused by exhaustion of the adrenal cortex. Some central mechanisms which could account for the biphasic changes in the plasma cortisol level and for disturbances of the hormone diurnal rhythmicity under conditions of prolonged stress are discussed.

The effect of castration on plasma cortisol level and time budget in farmed guanaco calves (Lama guanicoe)

2002 ◽  
Vol 2002 ◽  
pp. 214-214
Author(s):  
B. Zapata ◽  
K. Fuentes ◽  
C. Bonacic ◽  
B. González ◽  
J.L. Riveros ◽  
...  
Keyword(s):  
Plasma Cortisol ◽  
Time Budget ◽  
Plasma Cortisol Level ◽  
Cortisol Concentration ◽  
Farm Animals ◽  
Physiological Changes ◽  
Routine Procedure ◽  
Male Aggression ◽  
Lama Guanicoe ◽  
Plasma Cortisol Concentration

Castration is a routine procedure for male farm animals. The ethics of castration are widely debated because the procedure may potentially result in pain and distress. The indications for early castration in farmed guanacos are: 1) prevention of aberrant behaviour in human-imprinted males, 2) elimination of inter-male aggression, so that males may be housed together or with females, 3) avoidance of accidental breeding (Fowler, 1998). In addition, it has been argued (Molony and Kent, 1997) that to study the pain response to castration is ethically acceptable as the overall welfare of the animal is improved by the procedure. Guanaco farming has been recently established in South America, and there is therefore little information available on how guanacos respond to castration. The purpose of this study was to assess pain in farmed guanacos. The hypothesis was that pain experienced by guanacos due to castration may be displayed in behavioural and physiological changes, as has been reported in lambs, calves and piglets. The study was carried out in 2001 on four-month-old farmed male guanaco. Changes in plasma cortisol concentration and the frequency of specific daytime behavioural postures and activities following castration are reported.

CORTISOL SECRETION RATE, GLUCOSE ENTRY RATE AND THE MAMMARY UPTAKE OF CORTISOL AND GLUCOSE DURING PREGNANCY AND LACTATION IN DAIRY COWS

1974 ◽  
Vol 62 (2) ◽  
pp. 371-383 ◽  
Author(s):  
J. Y. F. PATERSON ◽  
J. L. LINZELL
Keyword(s):  
Blood Flow ◽  
Milk Yield ◽  
Plasma Cortisol ◽  
Cortisol Concentration ◽  
Secretion Rate ◽  
Cortisol Secretion ◽  
Entry Rate ◽  
Concentration Difference ◽  
Plasma Cortisol Concentration ◽  
Lactating Cows

SUMMARY Glucose entry rate was measured by primed infusion of [2-3H]glucose, and cortisol secretion rate by infusion of [1,2-3H2]cortisol, in two cows from 142 days before calving to day 287 of lactation. Mammary blood flow and the mammary uptake of glucose and cortisol were also measured. In late pregnancy, cortisol secretion rate was 8·6 ± 3·17 (s.d.) μg/min and plasma cortisol concentration was 1·8 ± 0·52 μg/l. During parturition in one animal the secretion rate was 92 μg/min and plasma cortisol concentration was 15 μg/l. During lactation the secretion rate (26·4 ± 7·14 μg/min) and plasma cortisol concentration (5·6 ± 0·73 μg/l) were significantly greater than in dry cows. The mammary uptake of cortisol was 3 to 4% of the secretion rate in both dry and lactating cows. Glucose entry rate was 5·77 ± 2·250 (s.d.) mg/min/kg0·75 in dry cows and there was no significant mammary uptake of glucose. During lactation the glucose entry increased to 9·45 ± 1·881 mg/min/kg0·75. Mammary uptake of glucose was 3·56 ± 1·949 mg/min/kg0·75. The non-mammary utilization of glucose, glucose entry less mammary uptake, was the same for dry and lactating cows. There was a good correlation between glucose entry and milk yield, and between mammary uptake of glucose and milk yield. Since the mammary arterio-venous glucose concentration difference was relatively constant, it is suggested that the change in mammary blood flow may determine the change in glucose uptake and milk yield.

Reduced Testosterone Levels in Cluster Headache: A Stress-Related Phenomenon?

Cephalalgia ◽  
1986 ◽  
Vol 6 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Fabio Facchinetti ◽  
Giuseppe Nappi ◽  
Claudio Cicoli ◽  
Giuseppe Micieli ◽  
Michela Ruspa ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Cluster Headache ◽  
Plasma Cortisol ◽  
Active Phase ◽  
Early Morning ◽  
Related Phenomenon ◽  
Cortisol Secretion ◽  
Plasma Cortisol Concentration ◽  
Episodic Cluster Headache ◽  
Cortisol Levels

The circadian changes in testosterone (T) and cortisol secretion and morning luteinizing hormone (LH) levels were evaluated in nine episodic cluster headache (CH) patients in active phase and in seven healthy volunteers, with collection of blood samples every 2 h for 24 h. CH showed a significant reduction of the 24-h integrated mean T value (mesor) (4.4 + 1.1 ng/ml; x ± SD) in comparison with controls (6.6 ± 0.8 ng/ml) ( P < 0.0l). Both groups had plasma T circadian rhythm with peak values in early morning, but in CH single cosinor analysis showed its absence in three out of nine CH patients. The rhythm showed an acrophase delay of 101 min in CH. Both patients and controls had a significant circadian rhythm of plasma cortisol concentration. CH patients, however, showed an acrophase delay of 106 min and significantly increased concentrations from 1200 h to 2000 h. Morning LH values were similar in the two groups. The reduced secretion of plasma T in CH patients in the active phase coexisted with an acrophase delay of its circadian rhythm. A similar delay was found in 24-h plasma cortisol levels. We suggest that stress accompanying attack expectancy in the active phase is the mechanism behind the elevated plasma cortisol levels. This in turn could reduce T concentrations, acting at the testicular level. These disturbances in internal chronoorganization support the hypothesis that cluster headache is basically a dyschronic disorder.

scholarly journals Light synchronization of the circadian rhythm of blood pressure and plasma cortisol concentration in a case of Shy-Drager syndrome in apallic state.

1987 ◽  
Vol 76 (5) ◽  
pp. 718-724 ◽  
Author(s):  
Masanari KUNIMOTO ◽  
Yoshikazu UGAWA ◽  
Masanobu SAKAMOTO ◽  
Kiyoharu INOUE ◽  
Manabu SAKUTA
Keyword(s):  
Blood Pressure ◽  
Circadian Rhythm ◽  
Plasma Cortisol ◽  
Cortisol Concentration ◽  
Plasma Cortisol Concentration

scholarly journals Circadian Rhythm of the Plasma Cortisol Level in Cases of Prolonged Coma

1977 ◽  
Vol 123 (1) ◽  
pp. 33-47 ◽  
Author(s):  
HIDEYA OKUYAMA ◽  
MINORU ENDO ◽  
YOSHIRO OHARA ◽  
SADAO TAKASE ◽  
KATSUYA ITAHARA
Keyword(s):  
Circadian Rhythm ◽  
Cortisol Level ◽  
Plasma Cortisol ◽  
Plasma Cortisol Level ◽  
Prolonged Coma

THE SPLANCHNIC AND HEPATIC UPTAKE OF CORTISOL IN CONSCIOUS AND ANAESTHETIZED SHEEP

1972 ◽  
Vol 55 (2) ◽  
pp. 335-350 ◽  
Author(s):  
J. Y. F. PATERSON ◽  
F. A. HARRISON
Keyword(s):  
Plasma Cortisol ◽  
Intestinal Tract ◽  
Hepatic Uptake ◽  
Cortisol Concentration ◽  
Constant Infusion ◽  
Cortisol Secretion ◽  
Plasma Cortisol Concentration ◽  
Partial Dissociation ◽  
Gastro Intestinal Tract ◽  
Venous Plasma

SUMMARY The uptake of cortisol by the gastro-intestinal tract and by the liver was estimated in sheep by measurement of [3H]cortisol concentrations in portal and hepatic venous plasma during constant infusion of tritium-labelled cortisol, with simultaneous measurement of plasma flows. The total splanchnic uptake of cortisol was 57 ± 4 (s.e.m.)% of the measured rate of cortisol secretion, 45% by the liver and the remainder by the gastro-intestinal tract. The splanchnic extraction of cortisol could be related to plasma flow, and was less efficient at higher flows. It could also be related to plasma cortisol concentration, and was more efficient at higher concentrations. The splanchnic uptake of cortisol was closely correlated with the flow of unbound cortisol into the region, and was 1·61 times that influx. There is therefore partial dissociation of plasma protein-bound cortisol during the splanchnic uptake. About 25% of secreted cortisol is converted to cortisone at extrahepatic sites, and is removed from plasma by the liver.

STIMULATION OF CARP INTERRENAL FUNCTION BY ADRENOCORTICOTROPHIN

1976 ◽  
Vol 68 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Z. ILAN ◽  
Z. YARON
Keyword(s):  
Protein Binding ◽  
Cortisol Level ◽  
Plasma Cortisol ◽  
Plasma Cortisol Level ◽  
Cortisol Concentration ◽  
Transient Rise ◽  
Competitive Protein Binding ◽  
Cortisol Release ◽  
Stimulation Of

SUMMARY The effect of ACTH on cortisol concentration in the plasma of the carp has been studied; cortisol was determined using a competitive protein-binding radioassay. Blood was sampled at 12.00 h (the diurnal minimum) by cardiac puncture. The plasma cortisol level of undisturbed carp (blood obtained 1–3 min after netting) was 46 ± 14 (s.e.m.) ng/ml. One hour after injection of ACTH (1·0 i.u./100 g body wt., i.m.) the level of cortisol increased to 415 ± 62 ng/ml and reached a maximum of 656 ± 62 ng/ml after 2 h. The level of cortisol in saline-injected control carp after 2 h was 72 ± 33 ng/ml. A transient rise of cortisol was noted in both groups 30 min after injection (315 ± 51, 315 ± 62 ng/ml). This was attributed to a surge of endogenous ACTH, presumably due to handling. Carp head kidneys were superfused in vitro. They released cortisol spontaneously, but the releasing rate declined exponentially and reached a minimum after 135 min. Addition of ACTH to the medium was followed by a prompt increase in cortisol release. The rate of cortisol release was maximal 30–45 min after addition of ACTH and was identical to the rate at the beginning of the superfusion.

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