Introduction Response to neuroendocrine stress begins with the activation of the hypothalamic–pituitary–adrenal (HPA) axis leading to the increase in stress hormones glucocorticoids (GCs). These hormones mediate adaptation to stress and also
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Miroslav Adzic, Jelena Djordjevic, Ana Djordjevic, Ana Niciforovic, Constantinos Demonacos, Marija Radojcic, and Marija Krstic-Demonacos
Catherine Garrel, Paul A Fowler, and Kaïs H Al-Gubory
to be one of the central elements in the mechanisms involved in cell function, growth, differentiation and death ( Valko et al . 2007 ). An increase in ROS generation beyond the ability of antioxidative protection, i.e. oxidative stress, potentially
Zhenhua Li, Tao Zhang, Hongyan Dai, Guanghui Liu, Haibin Wang, Yingying Sun, Yun Zhang, and Zhiming Ge
( Ferri & Kroemer 2001 ) and it is involved in several important functions such as the folding of secretory and membrane proteins. Various conditions can disturb the functions of the ER and result in ER stress (ERS). These conditions include ER-Ca 2
M. Rand-Weaver, T. G. Pottinger, and J. P. Sumpter
ABSTRACT
The preliminary finding that plasma levels of somatolactin (SL) were markedly elevated following stress caused by confinement in chinook salmon (Oncorhynchus tshawytscha) prompted a more detailed study of SL dynamics during stress. SL levels have been determined in the plasma of rainbow trout (Oncorhynchus mykiss) during exposure to acute (0–30 min) and short (0–24 h) periods of stress resulting from handling and confinement. The results show that SL levels increase rapidly within minutes following the onset of stress, reach a peak between 1 and 2 h, decline over the next 3 h, and then show an additional increase again by 24 h. During acute stress caused by confinement, the increase in plasma SL levels occurred within 2 min, thus showing a more rapid response than cortisol. This suggests that the response is mediated directly by the hypothalamus and is not a result of a feedback mechanism. The results also demonstrate that SL secretion in response to stress is at least partially under genetic control. In the short-term stress experiment, progeny of fish selected as high responders or low responders to stress, based on the magnitude of the plasma cortisol levels induced by stress, were used, and these fish showed similarly accentuated or attenuated release of SL following stress. These results clearly demonstrate that non-specific environmental stress causes rapid activation of SL-secreting cells in the pars intermedia, suggesting that this hormone has an important role in the adaptive response of fish to stress.
Journal of Endocrinology (1993) 138, 509–515
Melissa F Jackson, Dung Luong, Dor Dor Vang, Dilip K Garikipati, James B Stanton, O Lynne Nelson, and Buel D Rodgers
had larger hearts, due to eccentric hypertrophy, and an enhanced stress response, due in part to enhanced Ca 2 + handling. Analysis of primary ventricular myocytes indicated that [Ca 2 + ] i transients and total cellular loads were greater in Mstn
Francesca Spiga, Louise R Harrison, Susan Wood, David M Knight, Cliona P MacSweeney, Fiona Thomson, Mark Craighead, and Stafford L Lightman
-Diehl 2000 ). Evidence for the involvement of AVP in the HPA axis response to stress includes the increased secretion of AVP into the pituitary portal circulation ( de Goeij et al . 1991 , 1992 , Chowdrey et al . 1995 ) increased AVP mRNA within the
Y Yang, J Cao, W Xiong, J Zhang, Q Zhou, H Wei, C Liang, J Deng, T Li, S Yang, and L Xu
It has been documented that stress or glucocorticoids have conflicting effects on memory under different conditions. However, it is not fully understood why stress can either impair or enhance memory. Here, we have examined the performance of six age groups of Wistar rats in a water maze spatial task to evaluate the effects of stress under different conditions. We found that the impairment or enhancement effect of an 'elevated platform' (EP) stress on memory was dependent on previous stress experience and on age. EP stress impaired memory retrieval in water maze naive animals, but enhanced rather than impaired memory retrieval in young water maze stress-experienced animals. Furthermore, exogenously applied corticosterone or foot shock stress before water maze training prevented the impairment of memory retrieval that should be induced by treatment with corticosterone or foot shock before the 'probe trial'. Again, memory retrieval was enhanced in young animals under these conditions, and this enhancement can be prevented by the glucocorticoid receptor antagonist RU 38486. Thus, glucocorticoid receptor activation not only induced impairment of memory but also increased the capacity of young animals to overcome a later stress. The present findings suggest that the effect of stress on memory can be switched from impairment to enhancement dependent on both stress experience and age.
Juriaan R Metz, Mark O Huising, Karin Leon, B M Lidy Verburg-van Kemenade, and Gert Flik
. 2003 a , 2004 a ). It is generally accepted that our understanding of mechanisms, which underlie immune–stress relations will improve our insights in health and welfare of fish in production systems, since stress is a potential factor causing increased
I. D. Gilham and B. I. Baker
ABSTRACT
This work examines the difference in responsiveness to stress which characterizes fish adapted to white and black backgrounds. Trout were maintained in black or white tanks for 2 weeks and then subjected to intermittent intense or moderate noise stress for periods between 1 h and 5 days, or to the stress of being injected daily with a large volume of liquid for 3 days. Plasma cortisol concentrations increased more readily and to a greater extent in fish from black tanks in response to moderate stress or brief intense stress. Dexamethasone suppressed the stress-induced rise of cortisol in white-adapted fish but was only partially effective in trout from black backgrounds. These differences in plasma cortisol between black- and white-adapted fish can be related to the different titres of plasma ACTH, apparently derived from the pars distalis.
Removal of the neurointermediate lobe (NIL) from black-adapted eels markedly depressed the normal rise in plasma cortisol elicited by noise stress. It is suggested that products from the NIL may modulate the stress response of the hypothalamo-pituitary axis although other routes through which background colour could affect the pituitary responsiveness to stress are also considered. In several cases, stress also enhanced the secretion of MSH from the NIL.
J. Endocr. (1985) 105, 99–105
F. E. BADRICK, R. W. BRIMBLECOMBE, and M. REISS
SUMMARY
Rats stressed by swimming in cold water (15° C) show a considerably decreased uptake of 32P by the thyroid gland, which is comparable with the decrease in the uptake of 131I. The 32P uptake of the adrenals is increased.
These changes are independent of the anterior lobe of the pituitary, since they also occur after hypophysectomy. It is assumed that they are caused by the increased production of vaso-constrictor substances, since treatment with adrenaline produced identical changes in the function of thyroid and adrenals in both intact and hypophysectomized rats.
The significance of these changes in formulating a concept of the physiological reaction of the organism to conditions of stress is discussed.
