Surplus dietary tryptophan reduces plasma cortisol and noradrenaline concentrations and enhances recovery after social stress in pigs

2005 ◽  
Vol 85 (4) ◽  
pp. 469-478 ◽  
Author(s):  
S KOOPMANS ◽  
M RUIS ◽  
R DEKKER ◽  
H VANDIEPEN ◽  
M KORTE ◽  
...  
1998 ◽  
Vol 157 (3) ◽  
pp. 425-432 ◽  
Author(s):  
SL Alexander ◽  
CH Irvine

Plasma cortisol is largely bound to corticosteroid-binding globulin (CBG), which regulates its bioavailability by restricting exit from capillaries. Levels of CBG may be altered by several factors including stress and this can influence the amount of cortisol reaching cells. This study investigated the effect of social instability on plasma concentrations of CBG, total and free (not protein bound) cortisol in horses. Horses new to our research herd ('newcomers') were confined in a small yard with four dominant resident horses for 3-4 h daily for 3-4 (n = 5) or 9-14 (n = 3) days. Jugular blood was collected in the mornings from newcomers before the period of stress began ('pre-stress'), and then before each day's stress. Residents were bled before stress on the first and thirteenth day. Residents always behaved aggressively towards newcomers. By the end of the stress period, all newcomers were subordinate to residents. In newcomers (n = 8) after 3-4 days of social stress, CBG binding capacity had fallen (P = 0.0025), while free cortisol concentrations had risen (P = 0.0016) from pre-stress values. In contrast, total cortisol did not change. In residents, CBG had decreased slightly but significantly (P = 0.0162) after 12 days of stress. Residents and newcomers did not differ in pre-stress CBG binding capacity, total or free cortisol concentrations. However, by the second week of stress, CBG binding capacity was lower (P = 0.015) and free cortisol higher (P = 0.030) in newcomers (n = 3) than in residents. Total cortisol did not differ between the groups. In conclusion social stress clearly affected the adrenal axis of subordinate newcomer horses, lowering the binding capacity of CBG and raising free cortisol concentrations. However, no effect of stress could be detected when only total cortisol was measured. Therefore, to assess adrenal axis status accurately in horses, it is essential to monitor the binding capacity of CBG and free cortisol concentrations in addition to total cortisol levels.


2001 ◽  
Vol 74 (3) ◽  
pp. 383-389 ◽  
Author(s):  
Katherine A. Sloman ◽  
Neil B. Metcalfe ◽  
Alan C. Taylor ◽  
Kathleen M. Gilmour

2020 ◽  
Vol 68 (4) ◽  
pp. 217-227 ◽  
Author(s):  
Lisanne J. Bulling ◽  
Isabella C. Bertschi ◽  
Céline C. Stadelmann ◽  
Tina Niederer ◽  
Guy Bodenmann

Zusammenfassung. Die vorliegende Arbeit stellt die bisherigen empirischen Befunde zur Sprachgrundfrequenz (f0) in Paargesprächen vor und untersucht, wie sich die f0 nach einer experimentellen Stressinduktion im anschließenden spontanen Gespräch zwischen den Partner_innen verändert, wie die f0 mit der verbalen Stressäußerung zusammenhängt und wie sie zwischen den beiden Partner_innen kovariiert. Von 128 heterosexuellen Paaren nahm jeweils eine Person pro Paar am Trier Social Stress Test (TSST) teil. Die dem TSST vorangehende und anschließende naturalistische Interaktion zwischen den Partner_innen wurde gefilmt und nach Gesprächsthema und Art der Stressäußerung kodiert. Wie vorherige Studien zur f0 im Paargespräch zeigte auch die vorliegende Studie, dass die f0 wichtige Informationen über die Partnerschaft enthält. Während eine Erhöhung der f0 in Gesprächen über einen paarinternen Stressor (d.h. bei Konfliktgesprächen) mit negativen Kommunikationsmustern einherging, zeigte die vorliegende Studie, dass die f0 bei Gesprächen über einen paarexternen Stressor (d.h. beim TSST) mit emotionsorientierten Stressäußerungen einherging, also einer für den Stressbewältigungsprozess förderlichen Art der Kommunikation. Die Oszillatorenmodelle zeigen darüber hinaus, dass eine Kopplung der f0 zwischen den Partner_innen besteht, was darauf hindeutet, dass die nicht gestressten Partner_innen auf die paraverbalen Stressäußerungen der gestressten Partner_innen mit ihren eigenen paraverbalen Stressäußerungen reagieren.


Author(s):  
Jenny J. W. Liu ◽  
Julia Gervasio ◽  
Kenneth Fung ◽  
Kristin Vickers

Abstract. This study examined whether the relationship between subjective and physiological outcomes of stress, and the responsivity to stressors, are affected by whether participants can see a visual display of their physiological output. Participants were randomly assigned to have a visible view of their physiological output readings, or to a condition in which physiological output readings were out of view. Participants individually completed a 30-min laboratory study including the modified Trier Social Stress Task. Both physiological markers of stress (heart rate and blood pressure) and subjective evaluations of stress (visual analog scale) were measured. Results found little congruency across subjective and physiological measures of stress. The visible visual display condition had elevated physiological arousal, while no group differences were observed in self-reported stress. Findings from the study provide insight into the use of visual physiological displays and hold practical implications for both the measurement of stress in research, and the development of wearable technologies without accompanying response strategies.


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