scholarly journals Patterns of Corticosterone Secretion in Migrating Semipalmated Sandpipers at a Major Spring Stopover Site

The Auk ◽  
2001 ◽  
Vol 118 (1) ◽  
pp. 79-91 ◽  
Author(s):  
David S. Mizrahi ◽  
Rebecca L. Holberton ◽  
Sidney A. Gauthreaux, Jr
Keyword(s):  
Fat Mass ◽  
Stress Responses ◽  
Energy Demand ◽  
Corticosterone Concentration ◽  
Stopover Site ◽  
Handling Stress ◽  
Corticosterone Secretion ◽  
Julian Date ◽  
Energetic Condition ◽  
Semipalmated Sandpipers

AbstractSeasonal changes in corticosterone metabolism may be in part responsible for mediating the changes in nutrient reserves before and during migration. To investigate the role of glucocorticoids in the migratory physiology of Semipalmated Sandpipers (Calidris pusilla), we compared plasma levels of corticosterone in response to capture and handling stress during prolonged stopovers in Delaware Bay during spring 1996 and 1997. Although Semipalmated Sandpipers showed significant stress responses to handling in both years, the magnitude of the response was significantly lower in 1997. We found no correlation between energetic condition and initial corticosterone concentration in either year, or between energetic condition and corticosterone concentration in samples collected 30 min after capture in 1996. However, energetic condition was positively correlated with corticosterone concentration in 30 min sample collected in 1997. Between-year differences in regression functions of energetic condition by Julian date suggested that birds were accumulating fat mass more rapidly, or arriving in better energetic condition during 1996 compared to 1997. Those differences were especially evident during the “early” stages (before 26 May) of stopover periods. In 1997, we found that birds sampled early in the season did not show a significant increase in corticosterone 30 min after capture, while birds sampled in early 1996 did. In both years, birds sampled during the “late” stages of stopover periods (after and including 26 May) showed significant stress response. Birds in relatively poor energetic condition, or with low rates of fat-mass gain, were less likely to secrete additional corticosterone in response to acute stress, possibly to protect skeletal muscle needed for migratory flight. Those results suggest that patterns of corticosterone secretion in sandpipers can be modified in response to changes in energy demand during the migratory period.

scholarly journals Corticosterone Secretion, Energetic Condition, and a Test of the Migration Modulation Hypothesis in the Hermit Thrush (Catharus Guttatus), A Short-Distance Migrant

The Auk ◽  
2004 ◽  
Vol 121 (4) ◽  
pp. 1094-1102 ◽  
Author(s):  
Jennifer A. Long ◽  
Rebecca L. Holberton
Keyword(s):  
Energy Reserves ◽  
Handling Stress ◽  
Corticosterone Secretion ◽  
Energy Needs ◽  
Energetic Condition ◽  
Migratory Songbirds ◽  
Baseline Corticosterone ◽  
Catharus Guttatus ◽  
Hermit Thrush ◽  
Migratory Period

AbstractRecent evidence suggests that migration may be extremely important in limiting populations of migratory songbirds. Understanding the relationship between changes in cor- ticosterone secretion and energy reserves during migration is essential to understanding how environmental conditions such as weather, food availability, predation pressure, and habitat quality may be affecting birds en route. Several studies have found that baseline corticosterone is often elevated, and response to capture and handling stress reduced (migration modulation hypothesis), in birds sampled during the migratory period. However, because neither corticos- terone secretion nor energetic condition within groups of birds sampled either in laboratory or in field varied significantly (Holberton et al. 1996, Holberton 1999), it was unknown whether corticosterone secretion could be modulated to track changes in energetic condition within the migratory period. Here, we investigated patterns of corticosterone secretion associated with variation in energetic condition in 18 free-living Hermit Thrushes (Catharus guttatus) sampled during autumn migration. Mean baseline corticosterone (mean ± SE) was 37.22 ± 7.70 ng mL−1 and increased during the 30-min interval up to 54.52 ± 6.01 ng mL−1. Lean birds were more likely to exhibit higher levels of baseline corticosterone and a reduced adrenocortical response, compared with birds that had greater energy reserves. Collectively, the results support the migration modulation hypothesis and illustrate that baseline and stress-induced corticosterone secretion can be modulated to meet the changing energy needs of birds during the migratory period.

Relationship between energetic condition and indicators of immune function in thrushes during spring migration

2008 ◽  
Vol 86 (7) ◽  
pp. 638-647 ◽  
Author(s):  
J. C. Owen ◽  
F. R. Moore
Keyword(s):  
Immune Response ◽  
Immune Function ◽  
Spring Migration ◽  
Hylocichla Mustelina ◽  
Catharus Ustulatus ◽  
Stopover Site ◽  
Lymphocyte Ratio ◽  
Energetic Condition ◽  
In Captivity ◽  
Immunoglobulin Gamma

Evidence suggests that the ability of an animal to maintain its immune system and (or) mount an immune response depends on its nutritional health and energetic condition. Migration is a period within an animal’s annual cycle when energetic condition varies, especially after a long, nonstop flight over a large ecological barrier. Our objective was to determine if measures of immune function in migrating Wood Thrush ( Hylocichla mustelina (J.F. Gmelin, 1789)), Swainson’s Thrush ( Catharus ustulatus (Nuttall, 1840)), Gray-cheeked Thrush ( Catharus minimus (Lafresnaye, 1848)), and Veery ( Catharus fuscescens (Stephens, 1817)) were related to the energetic condition of the birds at a stopover site during spring migration. We present data on total leukocyte, lymphocyte, and heterophil counts, heterophil/lymphocyte ratio, serum immunoglobulin gamma G (IgG) concentration, and immune response to phytohemagglutinin. Thrushes arriving at the stopover site in poor energetic condition had low leukocyte and lymphocyte counts. Heterophil/lymphocyte ratio, heterophil count, and IgG concentration were not related to energetic condition. Furthermore, immune response to phytohemagglutinin was positively related to change in mass and days spent in captivity, suggesting that immune function may improve during stopover. We suggest that migrating thrushes arriving at a stopover site in poor energetic condition may also be in poor immunological condition and may have increased susceptibility to disease or parasite infection.

Adrenocortical responses of ducks to treadmill exercise

1982 ◽  
Vol 94 (1) ◽  
pp. 141-146 ◽  
Author(s):  
S. Harvey ◽  
J. G. Phillips
Keyword(s):  
Treadmill Exercise ◽  
Plasma Corticosterone ◽  
Pretreatment Level ◽  
Corticosterone Concentration ◽  
Domestic Ducks ◽  
Corticosterone Secretion ◽  
Corticosterone Response ◽  
Response To Exercise ◽  
Adrenocortical Responses ◽  
Stationary Control

The influence of treadmill exercise on corticosterone secretion has been determined in domestic ducks. In birds unused to such exercise the concentrations of plasma corticosterone were markedly increased (> fourfold) after 15 or 30 min of treadmill exercise (1·1 km/h at 3 ° grade) and the level remained high (between 30 and 40 ng/ml) throughout 90 min of exercise. This increase in corticosterone secretion accompanied a similar increase in colon temperature and was independent of the plasma glucose level. After exercise the corticosterone concentration declined to the pretreatment level within 60 min of recovery. In birds used to the exercise the corticosterone response to a standard (30 min) period of exercise was diminished (by 77·6% in comparison with untrained birds and was no greater than the response (1·7-fold) in stationary control birds after handling and bleeding. The diminution of the corticosterone response to exercise may be due to the trained birds becoming fitter and better able to perform the work involved.

Effect of adenosine analogues on plasma corticosterone concentration in rats

1992 ◽  
Vol 127 (5) ◽  
pp. 471-475 ◽  
Author(s):  
Edmund Przegaliński ◽  
Bogusława Budziszewska ◽  
Anna Grochmal
Keyword(s):  
Adenosine Receptor ◽  
Corticosterone Level ◽  
Plasma Corticosterone ◽  
Receptor Antagonists ◽  
Corticosterone Concentration ◽  
Adenosine Analogues ◽  
Negative Results ◽  
Corticosterone Secretion ◽  
Corticosterone Response ◽  
Pharmacological Blockade

In this study we examined the effect of the adenosine analogues: N6-cyclohexyladenosine, L-N6-phenylisopropyladenosine and 5′-N-ethylcarboxamidoadenosine on the plasma corticosterone concentration in rats. It was found that N6-cyclohexyladenosine (0.1–3.0 mg/kg), L-N6-phenylisopropyladenosine (0.1–1.0 mg/kg) and 5′-N-ethylcarboxamidoadenosine (0.01–1.0 mg/kg) dose-dependently increased the plasma corticosterone level. The effects of N6-cyclohexyladenosine (0.1 mg/kg) and L-N6-phenylisopropyladenosine (0.1 mg/kg) were completely blocked in animals pretreated with dexamethasone (3 × 1 mg/kg), as well as in animals with a pharmacological blockade of the release of hypothalamic corticotropin-releasing factor induced by chloropromazine (10 mg/kg), morphine (20 mg/kg) and nembutal (25 mg/kg), whereas the corticosterone response to 5′-N-ethylcarboxamidoadenosine (0.01 mg/kg) was blocked in dexamethasone-pretreated rats only. On the other hand, the adenosine receptor antagonists: 8-(p-sulfophenyl)-theophylline (30 mg/kg), 8-phenyltheophylline (10 and 30mg/kg), 1,3-dipropyl-8-(2-amino-4-chloro)-phenylxanthine (1 and 3 mg/kg) and 1,3-dipropyl-7-methylxanthine (1 mg/kg) did not affect the corticosterone response to N6-cyclohexyladenosine, L-N6-phenylisopropyladenosine or 5′-N-ethylcarboxamidoadenosine. The obtained results indicate that N6-cyclohexyladenosine and L-N6-phenylisopropyladenosine stimulate the corticosterone secretion at the hypothalamic level, whereas 5′-N-ethylcarboxamidoadenosine is likely to act at the pituitary level. Although the effects produced by the adenosine analogues show that both A1 and A2 receptors are involved in the corticosterone response, negative results of the interaction studies with adenosine receptor antagonists indicate that further experiments are necessary to elucidate this problem.

THE EFFECTS OF HYPOPHYSECTOMY ON ADRENOCORTICAL FUNCTION IN THE DUCK (ANAS PLATYRHYNCHOS)

1971 ◽  
Vol 49 (3) ◽  
pp. 437-457 ◽  
Author(s):  
E. L. BRADLEY ◽  
W. N. HOLMES
Keyword(s):  
Mammalian Species ◽  
Compartment Model ◽  
Liver Glycogen ◽  
Plasma Corticosterone ◽  
Adrenocortical Function ◽  
Metabolic Clearance ◽  
General Effect ◽  
Corticosterone Concentration ◽  
Peripheral Plasma ◽  
Corticosterone Secretion

SUMMARY The general effect of chronic hypophysectomy on organ and body weights, liver glycogen, blood glucose, peripheral plasma corticosterone concentrations, and blood pressure in the duck were similar to those described for several mammalian species. The disappearance and distribution of radioactivity after the administration of [1,2-3H]corticosterone and [1,2-3H]aldosterone was studied according to a single compartment model system. When compared with sham-operated ducks, the apparent volumes of distribution and the biological half-lives of radioactivity in hypophysectomized ducks were significantly increased, and the estimated metabolic clearance rates of [1,2-3H] corticosterone and [1,2-3H]aldosterone were significantly decreased. The patterns of distribution of radioactivity and the rate of metabolism of both hormones returned towards normal when the chronically hypophysectomized ducks were treated with corticotrophin (ACTH). Fourteen days after hypophysectomy the peripheral plasma concentration of corticosterone and the estimated rate of corticosterone secretion by the adrenal fell to 10 and 4%, respectively, of the values observed in sham-operated birds. Examinations of the peripheral plasma corticosterone concentration during the first 30 min after the removal of the adenohypophysis indicated a mean biological half-life for endogenous corticosterone of 13·7 min. The rates of appearance of radioactivity in the bile, intestine and cloaca of the hypophysectomized birds suggested substantial declines in the rates of aldosterone and corticosterone metabolism. These declines could not be accounted for by the reduced rate of glomerular filtration in the hypophysectomized bird. Replacement therapy with ACTH restored the excretory patterns of both steroids towards normal. The quantitative similarities between the effects of hypophysectomy in the duck and several mammalian species make it unnecessary to postulate either a high degree of adrenal autonomy or an extrahypophysial source of ACTH in the control of adrenocortical function in the duck.

Effect of forager density on feeding rates in spring-staging Semipalmated Sandpipers (Calidris pusilla) using different foraging modes

2018 ◽  
Vol 96 (9) ◽  
pp. 996-1001 ◽  
Author(s):  
Ivana Novcic ◽  
Guy Beauchamp
Keyword(s):  
Delaware Bay ◽  
Nearest Neighbour ◽  
Feeding Rates ◽  
Stopover Site ◽  
Neighbour Distance ◽  
Short Intervals ◽  
Foraging Modes ◽  
Calidris Pusilla ◽  
Spring Stopover ◽  
Semipalmated Sandpipers

We examined the influence of the density of foragers on feeding rates of Semipalmated Sandpipers (Calidris pusilla (Linnaeus, 1766)) while using different foraging modes at a spring stopover site in Delaware Bay, USA. Using dynamic estimates of interindividual distances obtained at short intervals of time, we explored how forager density affected feeding rates when Semipalmated Sandpipers used visual pecking or tactile probing. Pecking rate significantly increased with interindividual distances, whereas probe rate was not affected by density. Our study also showed that in fast-moving foragers, such as Semipalmated Sandpipers, in which the number of nearby foragers and distance to the nearest neighbour continuously change throughout the foraging bout, pecking rates are more affected by nearest neighbour distance than by the number of foragers in their immediate vicinity. In addition, our study implies that foragers using different foraging modes might be differently affected by nearby competitors perhaps in response to prey disturbance by neighbours.

scholarly journals Proteomic Profile of Glyphosate-Resistant Soybean under Combined Herbicide and Drought Stress Conditions

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2381
Author(s):  
Rafael Fonseca Benevenuto ◽  
Caroline Bedin Zanatta ◽  
Miguel Pedro Guerra ◽  
Rubens Onofre Nodari ◽  
Sarah Z. Agapito-Tenfen
Keyword(s):  
Adverse Effects ◽  
Stress Responses ◽  
Energy Demand ◽  
Interaction Network ◽  
Metabolic Cost ◽  
Stress Conditions ◽  
Stress Factors ◽  
Gm Plants ◽  
Abiotic Stressors ◽  
Gm Soybean

While some genetically modified (GM) plants have been targeted to confer tolerance to abiotic stressors, transgenes are impacted by abiotic stressors, causing adverse effects on plant physiology and yield. However, routine safety analyses do not assess the response of GM plants under different environmental stress conditions. In the context of climate change, the combination of abiotic stressors is a reality in agroecosystems. Therefore, the aim of this study was to analyze the metabolic cost by assessing the proteomic profiles of GM soybean varieties under glyphosate spraying and water deficit conditions compared to their non-transgenic conventional counterparts. We found evidence of cumulative adverse effects that resulted in the reduction of enzymes involved in carbohydrate metabolism, along with the expression of amino acids and nitrogen metabolic enzymes. Ribosomal metabolism was significantly enriched, particularly the protein families associated with ribosomal complexes L5 and L18. The interaction network map showed that the affected module representing the ribosome pathway interacts strongly with other important proteins, such as the chloro-plastic gamma ATP synthase subunit. Combined, these findings provide clear evidence for increasing the metabolic costs of GM soybean plants in response to the accumulation of stress factors. First, alterations in the ribosome pathway indicate that the GM plant itself carries a metabolic burden associated with the biosynthesis of proteins as effects of genetic transformation. GM plants also showed an imbalance in energy demand and production under controlled conditions, which was increased under drought conditions. Identifying the consequences of altered metabolism related to the interaction between plant transgene stress responses allows us to understand the possible effects on the ecology and evolution of plants in the medium and long term and the potential interactions with other organisms when these organisms are released in the environment.

Enhanced corticosterone-binding capacity in plasma after stimulation of the rat adrenal cortex: the possibility of a simultaneous release of protein and corticosterone

1987 ◽  
Vol 112 (1) ◽  
pp. 33-41 ◽  
Author(s):  
J. R. Bassett
Keyword(s):  
Binding Capacity ◽  
Specific Binding ◽  
Binding Protein ◽  
Plasma Concentrations ◽  
Plasma Corticosterone ◽  
Initial Increase ◽  
Scatchard Analysis ◽  
Corticosterone Concentration ◽  
Handling Stress ◽  
Corticosteroid Binding Globulin

ABSTRACT Exposure of rats to either footshock or handling stress produced a significant increase in both plasma corticosterone concentration and specific binding capacity. Non-specific binding was eliminated using the synthetic glucocorticoid, dexamethasone. The increase in both plasma corticosterone and specific binding capacity was biphasic following exposure to footshock. Adrenalectomy and pretreatment with betamethasone abolished both phases of the enhanced binding capacity and plasma steroid concentration. Intraperitoneal injection of ACTH (1–24) in animals pretreated with betamethasone resulted in a biphasic rise in plasma concentrations of corticosterone but only the initial increase in binding capacity. Dissociation constant (Kd) values, determined by Scatchard analysis, for adrenalectomized and betamethasone-pretreated animals were 546 and 556 pmol/l respectively. These values were significantly different from the Kd in animals with functional adrenals (631 pmol/l). The results are discussed in the light of a possible specific corticosteroid-binding globulin (CBG)-like binding protein of adrenal origin released in conjunction with corticosterone. This binding protein has a lower affinity for corticosterone and a shorter half-life than CBG. J. Endocr. (1987) 112, 33–41

Sign in / Sign up

Export Citation Format

Share Document