Ambient temperature and pregnancy influence cortisol levels in female guinea pigs and entail long-term effects on the stress response of their offspring

2011 ◽  
Vol 171 (3) ◽  
pp. 275-282 ◽  
Author(s):  
C.L. Michel ◽  
O. Chastel ◽  
X. Bonnet
2017 ◽  
Vol 117 (10) ◽  
pp. 1351-1357 ◽  
Author(s):  
Erik Höglund ◽  
Øyvind Øverli ◽  
Madelene Å. Andersson ◽  
Patricia Silva ◽  
Danielle Caroline Laursen ◽  
...  

AbstractComparative models suggest that effects of dietary tryptophan (Trp) on brain serotonin (5-hydroxytryptamine; 5-HT) neurochemistry and stress responsiveness are present throughout the vertebrate lineage. Moreover, hypothalamic 5-HT seems to play a central role in control of the neuroendocrine stress axis in all vertebrates. Still, recent fish studies suggest long-term effects of dietary Trp on stress responsiveness, which are independent of hypothalamic 5-HT. Here, we investigated if dietary Trp treatment may result in long-lasting effects on stress responsiveness, including changes in plasma cortisol levels and 5-HT neurochemistry in the telencephalon and hypothalamus of Atlantic salmon. Fish were fed diets containing one, two or three times the Trp content in normal feed for 1 week. Subsequently, fish were reintroduced to control feed and were exposed to acute crowding stress for 1 h, 8 and 21 d post Trp treatment. Generally, acute crowding resulted in lower plasma cortisol levels in fish treated with 3×Trp compared with 1×Trp- and 2×Trp-treated fish. The same general pattern was reflected in telencephalic 5-HTergic turnover, for which 3×Trp-treated fish showed decreased values compared with 2×Trp-treated fish. These long-term effects on post-stress plasma cortisol levels and concomitant 5-HT turnover in the telencephalon lends further support to the fact that the extrahypothalamic control of the neuroendocrine stress response is conserved within the vertebrate lineage. Moreover, they indicate that trophic/structural effects in the brain underlie the effects of dietary Trp treatment on stress reactivity.


2013 ◽  
Vol 47 (4) ◽  
pp. 376-381 ◽  
Author(s):  
Mihaela Jurdana ◽  
Maja Cemazar ◽  
Katarina Pegan ◽  
Tomaz Mars

Abstract Background. Long term effects of different doses of ionizing radiation on human skeletal muscle myoblast proliferation, cytokine signalling and stress response capacity were studied in primary cell cultures. Materials and methods. Human skeletal muscle myoblasts obtained from muscle biopsies were cultured and irradiated with a Darpac 2000 X-ray unit at doses of 4, 6 and 8 Gy. Acute effects of radiation were studied by interleukin - 6 (IL-6) release and stress response detected by the heat shock protein (HSP) level, while long term effects were followed by proliferation capacity and cell death. Results. Compared with non-irradiated control and cells treated with inhibitor of cell proliferation Ara C, myoblast proliferation decreased 72 h post-irradiation, this effect was more pronounced with increasing doses. Post-irradiation myoblast survival determined by measurement of released LDH enzyme activity revealed increased activity after exposure to irradiation. The acute response of myoblasts to lower doses of irradiation (4 and 6 Gy) was decreased secretion of constitutive IL-6. Higher doses of irradiation triggered a stress response in myoblasts, determined by increased levels of stress markers (HSPs 27 and 70). Conclusions. Our results show that myoblasts are sensitive to irradiation in terms of their proliferation capacity and capacity to secret IL-6. Since myoblast proliferation and differentiation are a key stage in muscle regeneration, this effect of irradiation needs to be taken in account, particularly in certain clinical conditions.


Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 570
Author(s):  
Innocent Mupunga ◽  
Ilse Janse van Rensburg ◽  
Nokuthula Luthuli ◽  
Ovokeroye A. Abafe ◽  
Leshweni J. Shai ◽  
...  

Analysis of body fluids and tissues of aflatoxin exposed individuals for the presence of aflatoxins and aflatoxin metabolites has emerged as a reliable indicator of exposure and metabolism of aflatoxins. However, current aflatoxin biomarkers are not appropriate for investigating the long-term effects of aflatoxin exposure. In this explorative study, we investigated the analysis of hair as a complementary or alternative matrix for the assessment of biomarkers of long-term aflatoxin exposure. Three groups of guinea pigs were orally dosed with 5 ugkg−1bw−1, 50 ugkg−1bw−1, and 100 ugkg−1bw−1 of AFB1. Urine and hair samples were collected on days 0, 1, 2, 3, 7, 30, 60, and 90 and analysed for AFB1 and AFM1 using UHPLC-MS/MS. AFB1 and AFM1 were detected in 75% and 13.6%, respectively, of the day 1 to day 7 urine samples. AFB1 was detected in hair samples collected from day 3 up to day 60. This is the first report to confirm the deposition of AFB1 in the hair of experimental animals. These findings indicate that hair analysis has the potential to provide an accurate long-term historical record of aflatoxin exposure with potentially important implications for the field of aflatoxin biomarkers.


2012 ◽  
Vol 37 (9) ◽  
pp. 1439-1447 ◽  
Author(s):  
Nienke M. Bosch ◽  
Harriëtte Riese ◽  
Sijmen A. Reijneveld ◽  
Martin P. Bakker ◽  
Frank C. Verhulst ◽  
...  

Endocrinology ◽  
2004 ◽  
Vol 145 (12) ◽  
pp. 5598-5604 ◽  
Author(s):  
R. S. Weisinger ◽  
J. R. Blair-West ◽  
P. Burns ◽  
D. A. Denton ◽  
B. Purcell ◽  
...  

Abstract The neuroendocrine hormones ACTH and corticotropin- releasing factor (CRF), which are involved in the stress response, have acute effects on arterial pressure. New evidence indicates that urocortin (UCN), the putative agonist for the CRF type 2 receptor, has selective cardiovascular actions. The responses to long-term infusions of these hormones, both peripherally and centrally, in conscious animals have not been studied. Knowledge of the long-term effects is important because they may differ considerably from their acute actions, and stress is frequently a chronic stimulus. The present experiments investigated the cardiovascular effects of CRF, UCN, and ACTH in conscious sheep. Infusions were made either into the lateral cerebral ventricles (icv) or iv over 4 d at 5 μg/h. UCN infused icv or iv caused a prolonged increase in heart rate (HR) (P < 0.01) and a small increase in mean arterial pressure (MAP) (P < 0.05). CRF infused icv or iv progressively increased MAP (P < 0.05) but had no effect on HR. Central administration of ACTH had no effect, whereas systemic infusion increased MAP and HR (P < 0.001). In conclusion, long-term administration of these three peptides associated with the stress response had prolonged, selective cardiovascular actions. The striking finding was the large and sustained increase in HR with icv and iv infusions of UCN. These responses are probably mediated by CRF type 2 receptors because they were not reproduced by infusions of CRF.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1590 ◽  
Author(s):  
Matthias Nemeth ◽  
Elisabeth Pschernig ◽  
Bernard Wallner ◽  
Eva Millesi

Non-invasive measurements of glucocorticoid (GC) concentrations, including cortisol and corticosterone, serve as reliable indicators of adrenocortical activities and physiological stress loads in a variety of species. As an alternative to invasive analyses based on plasma, GC concentrations in saliva still represent single-point-of-time measurements, suitable for studying short-term or acute stress responses, whereas fecal GC metabolites (FGMs) reflect overall stress loads and stress responses after a species-specific time frame in the long-term. In our study species, the domestic guinea pig, GC measurements are commonly used to indicate stress responses to different environmental conditions, but the biological relevance of non-invasive measurements is widely unknown. We therefore established an experimental protocol based on the animals’ natural stress responses to different environmental conditions and compared GC levels in plasma, saliva, and fecal samples during non-stressful social isolations and stressful two-hour social confrontations with unfamiliar individuals. Plasma and saliva cortisol concentrations were significantly increased directly after the social confrontations, and plasma and saliva cortisol levels were strongly correlated. This demonstrates a high biological relevance of GC measurements in saliva. FGM levels measured 20 h afterwards, representing the reported mean gut passage time based on physiological validations, revealed that the overall stress load was not affected by the confrontations, but also no relations to plasma cortisol levels were detected. We therefore measured FGMs in two-hour intervals for 24 h after another social confrontation and detected significantly increased levels after four to twelve hours, reaching peak concentrations already after six hours. Our findings confirm that non-invasive GC measurements in guinea pigs are highly biologically relevant in indicating physiological stress responses compared to circulating levels in plasma in the short- and long-term. Our approach also underlines the importance of detailed investigations on how to use and interpret non-invasive measurements, including the determination of appropriate time points for sample collections.


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