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Query: UMLS:C0848237 (acute stress)
 4,619 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The assumption that the acute response to stress is adaptive is pervasive in the literature, but there is little direct evidence regarding potential positive fitness consequences of an acute stress response. If acute glucocorticoid (GC) elevation increases lifetime reproductive success (fitness), in what contexts does this occur, and through what combination of effects on annual reproductive output and interannual survival? Here we examine the framework under which most comparative acute GC studies fall, evaluate the commonalities of those studies in the light of expected fitness effects, and suggest methods to better examine the potentially beneficial effects of the acute GC response for free living animals. An overwhelming majority of papers from this area examine environmental-physiological-social effects on GC reactivity. Fewer evaluate intermediate performance measures (fitness proxies). We could only find 11 that directly examine GC effects on reproductive output and survival. The environment-GC-performance papers suggest that greater GC reactivity favors self-maintenance behavior (survival) at the expense of current reproduction. However, the two studies that directly address GC reactivity and fitness (2 of the 11) find the opposite effect (greater GC reactivity predicts lower annual survival). We suggest that it is time to move past simple evaluation of factors regulating GC secretion. These studies will be much richer and informative if researchers include performance and fitness measures. We especially support incorporating and testing ideas of context dependency, coping strategies, and possible fluctuating selection pressures when considering the fitness benefits of the acute GC response.
Gen Comp Endocrinol 2008 Jul
PMID:In search of relationships between the acute adrenocortical response and fitness. 1860 55

In this study, the consequences of the exposure of rainbow trout (Oncorhynchus mykiss) to a brief stress during early development were explored on the later response of fingerlings to stress. Firstly, we analyzed the ontogeny of cortisol production and that of the initial cortisol response to stress in developing fish. It is only at the eyed stage that the embryos started to produce some basal cortisol. The HPI (hypothalamic-pituitary-interrenal axis) was however not functional before hatching, as exposure of the embryos to a stress did not trigger any cortisol response. A cortisol response to an acute stress was detected 9 days after hatching. In a second set of experiments, we showed that a very brief stress applied at 3 different early stages (eyed, hatching, and yolk resorption) reduced the later cortisol response to stress of 5-month-old fingerlings. This reduction is not likely to be due to alterations in the fish interrenal sensitivity because the 5-month-old fingerlings responded to ACTH treatment (only one dose tested) within the same magnitude as the fish that were not stressed during early development. An experimentally induced increase in egg cortisol just after fertilization also induced a reduction in stress sensitivity of 5 month old fingerlings, which was dose-dependent This study shows for the first time that the responsiveness of the corticotrope axis in 5-6 months old rainbow trout was influenced both by early stress exposure and by initial egg cortisol levels. Whether the HPI was functional or not at the time the initial stress was applied only had a small influence on the later unambiguous effect of early stress exposure.
Gen Comp Endocrinol 2008 Sep 15
PMID:Plasma cortisol response to stress in juvenile rainbow trout is influenced by their life history during early development and by egg cortisol content. 1867 77

As cities expand worldwide, understanding how species adapt to novel urban habitats will become increasingly important to conservation. The adrenocortical stress response enables vertebrates to cope with novel environmental challenges to homeostasis. We examined total and estimates of free baseline and stress-induced corticosterone (CORT) concentrations and CORT binding globulin (CBG) levels in five passerine species within and around Phoenix, Arizona. We tested whether baseline and stress-induced CORT patterns differed among species living at varying densities in Phoenix and tested the hypothesis that, for species capable of successfully colonizing cities, individuals living in urban areas have a decreased acute stress response compared to individuals living in native desert. Baseline total CORT levels were generally similar in urban and rural birds. Capture and handling stress typically produced greater total CORT responses in urban birds than in rural birds, although these responses differed as a function of the life history stage (non-breeding, breeding or molt). CBG binding capacity did not change with life history stage or locality. Estimated free CORT concentrations differed less between groups than total CORT concentrations. Urban birds showed less variability in stress responses across life history stages than rural birds. We propose that more predictable resources in the city than in rural areas may decrease the need to vary stress responsiveness across life history stages. The results highlight the species-specific effects of urbanization on stress physiology and the difficulty to predict how urbanization impacts organisms.
Gen Comp Endocrinol 2009 Feb 01
PMID:Corticosterone and corticosteroid binding globulin in birds: relation to urbanization in a desert city. 1911 55

The white sturgeon, Acipenser transmontanus, is a primitive bony fish that is recognized as an important emerging species for aquaculture. However, many aspects of its stress and reproductive physiology remain unclear. These processes are controlled by various steroid hormones. In order to investigate the regulation of steroidogenesis associated with acute stress in sturgeon, a cDNA-encoding steroidogenic acute regulatory protein (StAR) was isolated from white sturgeon. The putative amino acid sequence of sturgeon StAR shares high homology (over 60%) with other vertebrates. Phylogenetic analysis grouped sturgeon StAR within Actinopterygii, but it was clearly segregated from teleost StARs. RT-PCR analysis revealed that transcripts were most abundant in yellow corpuscles found throughout the kidney and weaker signals were detected in gonad and kidney. Very weak signals were also detected in brain and spleen by quantitative real-time PCR. In situ hybridization revealed that StAR is expressed in the cells of yellow corpuscles. No significant changes in StAR gene expression were detected in response to an acute handling stress. These results suggest that StAR is highly conserved throughout vertebrates, but the expression of the functional protein during the stress response may be partially regulated post-transcriptionally.
Gen Comp Endocrinol 2009 Jun
PMID:Steroidogenic acute regulatory protein in white sturgeon (Acipenser transmontanus): cDNA cloning, sites of expression and transcript abundance in corticosteroidogenic tissue after an acute stressor. 1924 13

The physiological responses to stressors, including hormonal profiles and associated tissue responsiveness have been extensively studied in teleosts, but the molecular mechanisms associated with this adaptive response are not well understood. The advent of cDNA microarray technology has transformed the field of functional genomics by revealing global gene expression changes in response to stressor exposures even in non-mammalian vertebrates, including fish. A unifying response in studies related to stressor exposure is activation of the hypothalamus-pituitary-interrenal (HPI) axis in fish, leading to cortisol release into the circulation. Here we will discuss the implications of some of the gene expression changes observed in response to acute stress in fish, while highlighting a role for cortisol in this adaptive stress response. As liver is a key organ for metabolic adjustments to stressors and also is a major target for cortisol action, the genomic studies pertaining to stress and glucocorticoid regulation have focused mainly on this tissue. The studies have identified several genes that are altered transiently after an acute stressor exposure in fish. A number of these stress-responsive genes were also modulated by glucocorticoid receptor activation, suggesting that elevation in cortisol levels during stressor exposure may be a key signal for target tissue molecular programming, essential for stress adaptation. The identification of regulatory gene networks that are stress activated, and modulated by cortisol, both in hepatic and extra-hepatic tissues, including gonads, brain, immune cells and gills, will provide a mechanistic framework to characterize the multifaceted role of cortisol during stress adaptation.
Gen Comp Endocrinol
PMID:Stress transcriptomics in fish: a role for genomic cortisol signaling. 1934 38

Changes in plasma corticosteroid-binding globulin (CBG) capacity can alter free plasma concentration and tissue availability of glucocorticoids (GC) and hence alter the organismal response to stress. However, CBG change in response to stress has not been extensively studied. While it is clear that chronic stress can causes CBG decline and in some species acute stressors can reduce CBG during the 30-60 min of the stressor, more long-term changes in CBG following an acute stressor has received less attention. Here we investigated corticosterone (CORT: the primary GC in birds) and CBG levels 24h after an acute stressor in a unique study system: Japanese quail divergently selected for CORT reactivity to acute stress. Using this model, we examined the interaction of selected CORT reactivity with CBG response to determine if CBG shows a delayed decline in response to an acute stressor and if that decline varies by selected genetic background. We found lowered CBG capacity, elevated total CORT and free CORT 24h after acute stress in all three quail groups. These results demonstrate for the first time in an avian species that exposure to an acute stressor can affect CBG and CORT 24h later.
Gen Comp Endocrinol 2010 Jan 15
PMID:How acute is the acute stress response? Baseline corticosterone and corticosteroid-binding globulin levels change 24h after an acute stressor in Japanese quail. 1968 48

Vertebrates respond to perceived stressors through increased plasma concentrations of glucocorticoids. However, there is considerable variation within and across species in the circumstances and degree to which glucocorticoid levels are elevated. We measured baseline and acute stress-induced levels of corticosterone of free-living, black-legged kittiwake chicks (Rissa tridactyla) across four consecutive breeding seasons in the northern Gulf of Alaska to determine the effect of hatching order and brood size on corticosterone levels of chicks. We sampled 12- to 15-day-old chicks from intact broods (i.e., no brood reduction) at three colonies from 2002-2005 (n=164). Baseline and stress-induced levels of corticosterone did not vary by hatching order or brood size. These results suggest that the adrenocortical function of kittiwake chicks from broods that survive intact through 12-15 days is not affected by either hatching order or brood size.
Gen Comp Endocrinol 2010 Mar 01
PMID:Effect of nestling status and brood size on concentration of corticosterone of free-living kittiwake chicks. 1969 42

While the role of corticosterone in mediating the response of birds to acute stress is well established, it has recently been proposed that a decrease in prolactin levels following stress may complement corticosterone in redirecting resources away from breeding activities and towards behaviors promoting immediate survival. Here, for the first time, we detail changes in the prolactin stress response of birds throughout the breeding cycle. We then discuss the modulation of the corticosterone and prolactin stress responses over successive stages of breeding, differing in reproductive value and parental effort. In a long-lived Procellariiform seabird, the Manx shearwater Puffinus puffinus, we found that prolactin levels decreased in response to acute stress during incubation and mid chick-rearing but increased in response to stress during late chick-rearing and in non parenting birds, a pattern similar to that previously described for mammals. The high corticosterone stress response in pre-breeders was consistent with predictions based on reproductive value, but a similar response during late chick-rearing was not. This probably reflected foraging effort and a heightened importance of the parents' own nutritional status at this stage of the season, in advance of post-breeding migration. We also found that baseline prolactin levels were maintained at high levels during chick-rearing and were only slightly lower during late chick-rearing and in failed breeders and non-breeders. These data suggest that prolactin may play a role in nestling care long beyond the brooding phase, that this is not due to birds spending long periods away from the colony and that prolactin secretion may be necessary for nest-guarding behavior.
Gen Comp Endocrinol 2010 Aug 01
PMID:Stress and parental care: Prolactin responses to acute stress throughout the breeding cycle in a long-lived bird. 2033 90

Serum corticosteroid levels are routinely measured as markers of stress in wild animals. However, corticosteroid levels rise rapidly in response to the acute stress of capture and restraint for sampling, limiting its use as an indicator of chronic stress. We hypothesized that serum corticosteroid binding globulin (CBG), the primary transport protein for corticosteroids in circulation, may be a better marker of the stress status prior to capture in grizzly bears (Ursus arctos). To test this, a full-length CBG cDNA was cloned and sequenced from grizzly bear testis and polyclonal antibodies were generated for detection of this protein in bear sera. The deduced nucleotide and protein sequences were 1218 bp and 405 amino acids, respectively. Multiple sequence alignments showed that grizzly bear CBG (gbCBG) was 90% and 83% identical to the dog CBG nucleotide and amino acid sequences, respectively. The affinity purified rabbit gbCBG antiserum detected grizzly bear but not human CBG. There were no sex differences in serum total cortisol concentration, while CBG expression was significantly higher in adult females compared to males. Serum cortisol levels were significantly higher in bears captured by leg-hold snare compared to those captured by remote drug delivery from helicopter. However, serum CBG expression between these two groups did not differ significantly. Overall, serum CBG levels may be a better marker of chronic stress, especially because this protein is not modulated by the stress of capture and restraint in grizzly bears.
Gen Comp Endocrinol 2010 Jun 01
PMID:Grizzly bear corticosteroid binding globulin: Cloning and serum protein expression. 2034 21

Testosterone (T) and glucocorticoids, such as corticosterone, have both been shown to be important for the way vertebrates in general, and birds specifically, react to their immediate environment. For both corticosterone and T, many sources of variation in plasma levels have been demonstrated. Interestingly, a small number of studies on bird species have indicated that acute stress can have a positive effect on plasma T levels, analogous to what has been observed for plasma corticosterone levels. Using captive male European starlings (Sturnus vulgaris), we provide the first evidence in songbirds of a (twofold) increase in plasma T levels after the onset of acute stress, as elicited with a capture-handling-restraint method, when comparing plasma T levels during the first 4 min with plasma T levels between 12 and 33 min. Furthermore, no significant change in plasma T levels was observed within the first 4 min after the onset of acute stress. Notably, although plasma corticosterone was also significantly elevated, the stress-induced change in levels of corticosterone and T were not significantly correlated. Our findings indicate that, when measuring plasma T levels, it may be essential to use a standardized method with fast capture and blood sampling (i.e. within 3-4 min), similar to the method for corticosterone sampling. Furthermore, it is necessary for future studies to examine the effect of using different capture techniques on measured plasma T levels, which may be of particular importance when interpreting T samples gathered in field studies.
Gen Comp Endocrinol 2010 Sep 15
PMID:Acute stress induces a rapid increase of testosterone in a songbird: implications for plasma testosterone sampling. 2060 23


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